Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL
SWITCHING REGULATOR
S-8335 Series
The S-8335 Series is a bias supply IC for a Multi Line Addressing (MLA)
driven LCD using a dual-line simultaneous selection mode. This IC
supports medium-sized LCD panels. Two step-up type and one inverter
type PFM control CMOS switching regulators supply the required positive
or negative power to the two MLA-driven LCD common drivers and
segment drivers. Because of its CMOS structure, the current consumption
of the S-8335 Series is extremely low, which makes it ideal for the LCD
power supply of portable equipment that requires low power consumption.
Also, an extremely low power consumption LCD module can be created by
using the S-8335 Series with the LCD common driver (HD66523R∗1:
Manufactured by Hitachi, Ltd.) and segment driver (HD66522∗1:
Manufactured by Hitachi, Ltd.).
∗
1:These drivers are able to support 1/240duty and 1/200duty.
Features
• Supports four types of LCD panels (1/240 duty, 1/200 duty, 1/160 duty, and 1/120 duty).
• Input voltage range: 2.4 to 5.0 V (The S-8335 can be driven by a single direct-coupled lithium battery.)
• Output voltage range
Common driver positive power supply (VRH) output voltage range(typ.value)
8.91 to 16.59 V (S-8335A240FT)
8.22 to 15.30 V (S-8335A200FT)
7.48 to 13.93 V (S-8335A160FT)
6.66 to 12.41 V (S-8335A120FT)
(This supply can be varied by on-chip 6-bit electric volume. Power MOSFET is built in.)
Common driver negative power supply (VRL) output voltage range(typ.value)
-6.87 to -12.80 V (S-8335A240FT)
-6.18 to -11.49 V (S-8335A200FT)
-5.44 to -10.13 V (S-8335A160FT)
-4.61 to -8.59 V (S-8335A120FT)
Segment driver positive power supply (VCH) output voltage range 2.0 to 3.8 V
Segment driver intermediate potential (VM) output voltage range 1.0 to 1.9 V
Icon positive power supply (VICON) output voltage range 1.0 to 2.2 V (This supply can be set arbitrarily
by external resistors.)
• Low current consumption
100 µA typ. (mode 1, VBAT = 3 V)
10 µA typ. (mode 2, VBAT = 3 V)
1 µA max. (mode 3, VBAT = 3 V)
• Triple operation mode function: Triple mode switching according to 2-bit input
Mode 1: Normal operation
Mode 2: Icon mode (reference voltage circuit- and regulator S-only operation)
Mode 3: Standby mode (power off)
• Power-off function
Stops step-up or step-down operation and short circuits VRH and VRL to VSS by on-chip and external
Nch transistors.
• Soft-start function: This function can be set according to an external capacitor (CSS).
• Oscillation frequency: 100 kHz ± 20 kHz, Duty = 50%
• Lead-free products
Applications
• Power supply for medium-sized LCD panel
Package Name
• 24-pin TSSOP package (PKG diagram code: FT024-A)
Seiko Instruments Inc.
1
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
Block Diagram
D3
L3
L1
D1
CL3
A
VRH
12
1
6
16
2
4
24
VOUT3
CONT3
VSTR_B
VCLK
3
21
Electric
volume
RESET
DC/DC P
VBAT
VDIN
VOUT1
CONT1
CL1
DC/DC U
PFM control
circuit
PFM control
circuit
5
R1
R2
17
DC/DC Q
MC1
23
22
PFM control
circuit
Mode
control
circuit
MC2
14
VQERR
20
VREFU
CREFU
Reference
voltage
generation
circuit
op-amp X
Oscillator
REG S
VDDX
VXO
REG T
VYO
VREGSF VREGSO VREGTF VREGTO
11
10
9
8
RS1
RS2
: small current VSS,
D2
F
RT1
VCH
13
VM
15
CSS
CRS1 VICON
18
op-amp Y
EXT2
7
19
L2
VRL
CL2
CRT1
RT2
: large current VSS
Figure 1 Block Diagram
Note:
Except for op-amp X, all of the power for the internal circuits of the S-8335 Series is supplied by the VBAT
pins. The power supply for op-amp X uses VOUT3, which is generated by stepping up VBAT using DC/DC U.
Short-circuit the VOUT3 and VDDX pins as shown in the figure above.
2
Seiko Instruments Inc.
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
Selection Guide
1. Product name
S−8335A XXX FT−TB−G
Package name (abbreviation)
Product type
240: 1/240 duty support
200: 1/200 duty support
160: 1/160 duty support
120: 1/120 duty support
2. Product list
S-8335AXXXFT Series
Bias Ratio
Common Driver Positive
Power Supply VRH
Output Voltage Range [V]
Common Driver Negative
Power Supply VRL
Output Voltage Range [V]
VRH_min
VRH_max
VRL_min
VRL_max
S-8335A240FT-TB-G
8.75
8.91
16.59
−6.87
−12.80
S-8335A200FT-TB-G
8.04
8.22
15.30
−6.18
−11.49
S-8335A160FT-TB-G
7.33
7.48
13.93
−5.44
−10.13
S-8335A120FT-TB-G
6.50
6.66
12.41
−4.61
−8.59
Note: VRH_min and VRL_min indicate the typical value of the VRH and VRL output voltage, respectively,
when the electric volume is set to the minimum, and VRH_max and VRL_max indicate the typical
value of the VRH and VRL output voltage, respectively, when the electric volume is set to the
maximum. Also, VRH_max is obtained from VRETGO × 7.136 and VRH_min is obtained from VRETGO ×
3.832, where VRETGO is the regulator T output voltage.
Seiko Instruments Inc.
3
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
Pin Assignment
24-pin TSSOP Package
Pin No.
Top view
CONT1
1
24
CONT3
VDIN
2
23
MC1
VCLK
3
22
MC2
VSTR_B
4
21
VOUT3
VSS
5
20
VREFU
VOUT1
6
19
VDDX
CSS
7
18
VXO
VREGTO
8
17
VSS
VREGTF
9
16
VBAT
VREGSO
10
15
EXT2
VREGSF
11
14
VQERR
VBAT
12
13
VYO
Pin Name
Function
1
CONT1
2
VDIN
External inductor 1 connection pin
Electric volume data input pin
3
VCLK
Electric volume clock input pin
4
VSTR_B
Electric volume strobe signal input pin
5
VSS
GND pin
6
VOUT1
Switching regulator P output voltage pin
7
CSS
Soft start capacitor connection pin
8
VREGTO
Regulator T output pin
9
VREGTF
Regulator T feedback input pin
10
VREGSO
Regulator S output pin
11
VREGSF
Regulator S feedback input pin
12
VBAT
Power supply pin
13
VYO
OP amplifier Y output pin
14
VQERR
Switching regulator Q output voltage monitoring pin
15
EXT2
Switching regulator Q external transistor connection pin
16
VBAT
Power supply pin
17
VSS
GND pin
18
VXO
OP amplifier X output pin
19
VDDX
OP amplifier X power supply pin
20
VREFU
Switching regulator U internal reference voltage pin
21
VOUT3
Switching regulator U output voltage pin
22
MC2
Operating mode control pin 2
23
MC1
Operating mode control pin 1
24
CONT3
External inductor 3 connection pin
Absolute Maximum Ratings
(Unless otherwise specified: TOPR=25°C)
Parameter
Symbol
VBAT pin voltage
VBAT
CONT1 pin voltage
VCONT1
CONT1 pin current
VOUT1 pin voltage
Unit
8
V
−0.3 to +20
V
ICONT1
300
mA
VOUT1
−0.3 to +20
V
EXT2 pin voltage
VEXT2
−0.3 to VBAT+20
V
EXT2 pin current
IEXT2
CONT3 pin voltage
VCONT3
CONT3 pin current
VOUT3 pin voltage
±50
mA
−0.3 to +8
V
ICONT3
200
mA
VOUT3
−0.3 to +8
V
VQERR pin voltage
VQERR
−0.3 to +8
V
VDDX pin voltage
VDDX
8
V
VXO pin voltage
VXO
−0.3 to VDDX+0.3
V
Other pin voltage
−0.3 to VBAT+0.3
V
650
mW
TOPR
−20 to +70
°C
TSTG
−40 to +125
°C
Power dissipation
PD
Operating temperature range
Storage temperature range
Note:
4
Ratings
Although this IC incorporates an electrostatic protection circuit, the user is urged to avoid
subjecting the circuit to an extremely high static electricity or voltage in excess of its
performance.
Seiko Instruments Inc.
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
Electrical Characteristics
Note:
The data specifications are based on measured results using recommended peripheral parts
(see
Recommended Peripheral Parts).
Common
(Unless otherwise specified: VBA T = 3.0 V, TOPR = 25°C)
Item
Min.
Typ.
Max.
Unit
Measurement
Circuit
2.4
3.0
5.0
V
−
−
100
200
µA
1
−
40
90
µA
1
−
10
20
µA
1
−
−
1.0
µA
1
VCH
1.6
−
−
V
1
VCL
−
−
0.4
V
1
Symbol
Input voltage
VBAT
Mode 1 current
consumption for full
oscillation
IMC11
Conditions
Current flowing from power supply pin VBAT.
Only regulator S and T resistance externally.
Maximum setting for electric volume. Output
voltage of DC/DC P, U, and Q are each
setting value × 0.9.
CONT1 and CONT3 are pulled up to 3 V via a
300 Ω resistor.
Mode 1 current
consumption for
stopped oscillation
IMC12
Current flowing from power supply pin VBAT.
Only regulator S and T resistance externally.
Maximum setting for electric volume. Output
voltage of DC/DC P, U, and Q are each
setting value × 1.2.
CONT1 and CONT3 are pulled up to 3 V via a
300 Ω resistor.
Mode 2 current
consumption
IMC2
Current flowing from power supply pin VBAT.
Only regulator S and T resistance externally.
Output voltage of DC/DC P, U, and Q are 0 V.
CONT1 and CONT3 are pulled up to 3 V via a
300 Ω resistor.
Mode 3 current
consumption
IMC3
Current flowing from power supply pin VBAT.
Only regulator S and T resistance externally.
Output voltage of DC/DC P, U, and Q are 0 V.
CONT1 and CONT3 are pulled up to 3 V via a
300 Ω resistor.
MC1, MC2, VDIN,
VCLK, VSTR_B
pin input voltage
Oscillator Part
(Unless otherwise specified: VBAT = 3.0 V, TOPR = 25°C)
Item
Symbol
Conditions
Min.
Typ.
Max.
Unit
Measurement
Circuit
Oscillation frequency
fOSC
80
100
120
kHz
1
Duty ratio
Duty
40
50
60
%
1
Seiko Instruments Inc.
5
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
VRH Generation Step-Up Type DC/DC P Part
(Unless otherwise specified: VBAT=3.0 V, TOPR = 25°C)
Item
Output voltage 1
Output voltage 2
Symbol
VOUT11
VOUT12
Conditions
Electric volume
at maximum,
IOUT1 = 100 µA
Electric volume
at minimum,
IOUT1 = 100 µA
Min.
Typ.
Max.
Unit
Measurement
Circuit
For S-8335A240FT,
VREGTO = 2.325 V
For S-8335A200FT,
VREGTO = 2.144 V
16.180
16.590
17.009
V
2
14.918
15.300
15.683
V
For S-8335A160FT,
VREGTO = 1.952 V
13.582
13.930
14.278
V
For S-8335A120FT,
VREGTO = 1.739 V
12.098
12.410
12.718
V
For S-8335A240FT,
VREGTO = 2.325 V
For S-8335A200FT,
VREGTO = 2.144 V
8.688
8.910
9.134
V
8.011
8.220
8.422
V
For S-8335A160FT,
VREGTO = 1.952 V
7.293
7.480
7.667
V
For S-8335A120FT,
VREGTO = 1.739 V
6.496
6.660
6.829
V
2
Switching
current
ISWP
VCONT1 = 0.4 V
60
85
−
mA
1
Switching
transistor
leakage
current
ISWQP
For mode 3 (25°C)
−
−
1
µA
1
For mode 3 (70°C)
−
−
10
µA
−
VOUT1 pin input
current
IVOUT1
For electric volume set to minimum
2
4
8
µA
1
VOUT1 pin sink
current
IVOUT1L
Mode 3, VOUT1 = 0.4 V
0.9
1.3
−
mA
1
Soft start time
Tss
Time until the error amplifier reference
voltage reaches 90% of the final value
of the regulator T output voltage.
10
15
35
ms
1
−
82
−
%
−
CRT1= 0.1 µF, CSS= 0.01 µF
Efficiency
6
EFFIP
Electric volume set to middle, IOUT1 = 1
mA
Seiko Instruments Inc.
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
DC/DC P Electric Volume Part
(Unless otherwise specified: VBAT = 3.0 V, TOPR = 25°C)
Item
Symbol
Min.
Typ.
Max.
Unit
Measurement
Circuit
For S-8335A240FT, VREGTO = 2.325 V
8.91±2.5%
−
16.59±2.5%
V
2
For S-8335A200FT, VREGTO = 2.144 V
8.22±2.5%
−
15.30±2.5%
V
For S-8335A160FT, VREGTO = 1.952 V
7.48±2.5%
−
13.93±2.5%
V
For S-8335A120FT, VREGTO = 1.739 V
6.66±2.5%
−
12.41±2.5%
V
Potential division
precision
−
−
2.5
%
Electric volume
resolution
−
1/63
−
Electric volume
adjustment range
VOUT
Conditions
Linearity error
2
2
−
−
1/2
LSB
2
Data setup time
tsc
5.0
−
−
µs
−
Data hold time
thc
5.0
−
−
µs
−
VCLK pulse width
tdc
0.5
4.17
−
µs
−
VCLK period
ttc
5.0
8.33
−
µs
−
VCLK↓ to VSTR_B ↓
tss
5.0
−
−
µs
−
VSTR_B pulse width
tda
5.0
−
−
µs
−
VSTR_B↑ to VCLK↑
ths
5.0
−
−
µs
−
D1
VDIN
D0
tsc
VCLK
next MSB
ttc
thc
tss
tda
tdc
ths
VSTR_B
Figure 2 Clock Timing
VDIN
VCLK
VSTR_B
H
−
−
Data 1
State
L
−
−
Data 0
−
L to H
−
Load data in shift register
−
−
L
Load shift register contents in latch
−
−
H
Hold latch data
Seiko Instruments Inc.
7
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
VRL Generation Inverter Type DC/DC Q Part
(Unless otherwise specified: VBAT = 3.0 V, TOPR = 25°C)
Item
Symbol
Conditions
Min.
Typ.
Max.
Unit
Measurement
Circuit
Comparator offset
VQEROF
VYO = 1.45 V
−20
0
+20
mV
1
EXT2 pin output current
IEXT2H
For VEXT2 = VBAT - 0.4 V
−5.3
−7.6
−
mA
1
IEXT2L
For VEXT2 = 0.4 V
7.4
10.5
−
mA
1
EFFIQ
Electric volume set to middle, IOUT2 = 1 mA
−
60
−
%
−
Efficiency
Step-up Type DC/DC U Part
(Unless otherwise specified: VBAT = 3.0 V, TOPR = 25°C)
Item
Symbol
Conditions
Min.
Typ.
Max.
Unit
Measurement
Circuit
2.97
3.05
3.12
V
2
Output voltage
VOUT3
For fixed VREFU = 2.90 V, IOUT3 = 100 µA
Switching current
ISWU
VCONT3 = 0.4 V
73
104
−
mA
1
Switching transistor leak
current
ISWQU
Mode 3
−
−
1.0
µA
1
VOUT3 pin off current
IVOUT3L
Mode 3, VOUT3 = 0.4 V
−
−
0.5
µA
1
Efficiency
EFFIU
Electric volume set to middle, IOUT3 = 1 mA
−
95
−
%
−
OP Amplifier X Part
(Unless otherwise specified: VBAT = 3.0 V, TOPR = 25°C)
Item
Symbol
Conditions
Output voltage
VXO
IOUTX = 50 µA, VREFU = 2.90 V
Output voltage 2
VXO2
For 1mA output
Current consumption
ISSX
VXO pin sink current
IVXOL
Mode 3, VXO = 0.4 V
Min.
Typ.
Max.
Unit
Measurement
Circuit
2.828
2.90
2.973
V
1
VXO - 0.08
−
VXO
V
1
−
10
20
µA
1
0.46
0.66
−
mA
1
OP Amplifier Y Part
(Unless otherwise specified: VBAT = 3.0 V, TOPR = 25°C)
Item
8
Symbol
Conditions
Min.
Typ.
Max.
Output voltage precision
VYOD
= (VXO-VYO)/VYO, no load at Y, IOUTX = 50 µA
0.98
−
1.02
VYO pin sink current
IVYOL
Mode 3, VYO = 0.4 V
0.46
0.66
−
Seiko Instruments Inc.
Unit
Measurement
Circuit
1
mA
1
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
Regulator S Part
(Unless otherwise specified: VBAT = 3.0 V, TOPR = 25°C)
Item
Output voltage
Symbol
VREGSO
Conditions
IOUTS = 50 µA,
Min.
Typ.
Max.
Unit
Measurement
Circuit
1.576
1.6
1.624
V
1
−
±50
−
ppm/°C
−
0.40
0.57
−
mA
1
RS1 = 210 kΩ, RS2 = 270 kΩ
Output voltage
temperature coefficient
∆VREGSO
/(VREGSO •
∆TOPR)
TOPR = -20°C to +70°C (when no RS1, RS2
temperature characteristics are taken into
account)
VREGSO pin sink
current
IVREGSOL
Mode 3, VREGSO = 0.4 V
Regulator T Part
(Unless otherwise specified: VBAT = 3.0 V, TOPR = 25°C)
Item
Output voltage
VREGTO pin sink current
Symbol
VREGTO
IVREGTOL
Min.
Typ.
Max.
Unit
Measurement
Circuit
S-8335A240FT
2.290
2.325
2.360
V
1
S-8335A200FT
2.112
2.14
2.176
V
S-8335A160FT
1.923
1.95
1.981
V
S-8335A120FT
1.713
1.74
1.765
V
0.46
0.65
−
mA
Conditions
For fixed VREGSO =
1.6 V, IOUTT=50 µA.
For RT1, RT2
values, see Recommended Peripheral
Parts.
Mode 3, VREGSO = 0.4 V
Seiko Instruments Inc.
1
9
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
Recommended Peripheral Parts (When VICON=1.6 V)
Part
L1, L2, L3
Value
Unit
150
µH
D1, D2, D3
Model No.
Remark
CDRH5D18-151
Manufactured by Sumida Electric Co., Ltd.
MA720
Manufactured by Matsushita Electric Components Co.,
Ltd. (Schottky type)
CL1
2.2
µF
CM316W5R225K25A
Ceramic type
CL2
2.2
µF
CM316W5R225K25A
Ceramic type
CL3
10
µF
F930J106MA
Tantalum type
MOSFET A
2SJ356
Pch MOSFET manufactured by NEC
MOSFET F
TM5211
Pch MOSFET manufactured by Toyoda Automatic Loom
Works, Ltd.
MOSFET C
2SJ463A
Pch MOSFET manufactured by NEC
MOSFET D, E, G
2SK3019
Nch MOSFET manufactured by ROHM
µF
CM21B105K10A
Ceramic type
1
µF
CM21B105K10A
Ceramic type
CL6
1
µF
CM21B105K10A
Ceramic type
CL7
1
µF
CM21B105K10A
Ceramic type
CREFU
2200
pF
CM105W5R222M10A
Ceramic type
CSS
0.01
µF
CM105W5R103M10A
Ceramic type
CR1, CR2
0.01
µF
CM105W5R103K25A
Ceramic type
CRS1
−
µF
CRT1
0.1
µF
CM105W5R104M10A
Ceramic type
1
µF
CM105Y5V105Z10A
Ceramic type
1
CL4
1
CL5
CVBAT1
CVBAT2
Ceramic type (capacitance added only when regulator S
oscillates)
µF
CM105Y5V105Z10A
Ceramic type
CMC1, CMC2,
CMC3
0.1
µF
CM105Y5V104Z10A
Ceramic type
CDIN, CCLK,
CSTR_B
1
µF
CM105Y5V105Z10A
Ceramic type
R1, R2
1
MΩ
210
kΩ
RS1
±0.5% precision
(100 + 110) kΩ, 100 kΩ replaced by thermistor.
Ishizuka Electronics Corporation thermistor 104HT (100
kΩ).
RS2
RT1
270
kΩ
Use when RS1 + RS2 > 100 kΩ
68
kΩ
S-8335A240FT (Use when RT1 + RT2 > 185 kΩ)
51
kΩ
S-8335A200FT (Use when RT1 + RT2 > 110 kΩ)
33
kΩ
S-8335A160FT (Use when RT1 + RT2 > 80 kΩ)
S-8335A120FT (Use when RT1 + RT2 > 65 kΩ)
13
kΩ
RT2
150
kΩ
RA1
470
kΩ
RA2
150
kΩ
RA3
150
kΩ
Note 1: The regulator S input (reference voltage generation circuit output) voltage has been trimmed
to 0.9 V when shipped. Also, the external resistance RS1 and RS2 of the recommended
peripheral parts have been set so that VICON=1.6 V. When a VICON value other than 1.6 V is
used, select the resistance RS1 and RS2 values to match the VICON voltage used. Also
change the RT1 and RT2 values at the same time, because the RT1 and RT2 values are
selected based on VICON=1.6 V.
Note 2: CRS1 is not usually necessary. Add the capacitance only when regulator S is oscillating.
Evaluate the actual device using capacitance value on the order of 0.1 µF.
Note 3: The output voltage precision does not include external resistance dispersion.
Seiko Instruments Inc.
10
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
Measurement Circuits
1:
1
24
CREFU
CRT1
RT1
RS1
VOUT3 MC2 MC1
CRS1
VOUT1
VDIN VCLK
VSTR_B
VREFU
CSS
RT2 RS2
CL6
12
VBAT VDDX
13
CL7
VEXT2
VQERR
CVBAT1
CVBAT2
CL5
CL4
2:
L1
1
24
L3
D3
D1
R2
CREFU
RT1
CR2
CRT1
PSW
CR1
RS1
D2
CRS1
MC2 MC1
R1
VDIN VCLK VSTR_B
RT2 RS2
12
CSS
CL6
VBAT
13
L2
CL7
CVBAT1 CL1
CVBAT2
VREFU
CL2
CL5 CL4 CL3
Figure 3 Measurement Circuits
Seiko Instruments Inc.
11
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
Operation
The S-8335 Series has two step-up type and one inverter type CMOS on-chip switching regulators. These
switching regulators employ the pulse frequency modulation (PFM) method to provide low current
consumption features.
1. Operation Overview
The output of the reference voltage generation circuit is the input to regulator S. The output of regulator
S is the input to regulator T. After the extremely steep rise has been blunted by an RC low-pass filter,
the output of regulator T becomes the DC/DC P reference voltage. The DC/DC P output (pin name:
VOUT1) that is controlled by the electric volume is obtained based on this reference voltage. The
DC/DC P output becomes the common driver positive power supply (VRH).
VRH is divided by internal resistors and becomes the input of OP amplifier X. The output (pin name:
VXO) of OP amplifier X becomes the segment driver positive power supply (VCH).
Also, the input voltage of OP amplifier X becomes the reference voltage of the DC/DC U error amplifier.
The DC/DC U output (pin name: VOUT3) is obtained so that it becomes 1.05 times larger than this
reference voltage. The DC/DC U output voltage can be used for the OP amplifier X power supply
voltage.
VCH is divided by internal resistors and becomes the input of OP amplifier Y. The output (pin name:
VYO) of OP amplifier Y becomes the segment driver intermediate potential (VM).
VM becomes the reference voltage of the DC/DC Q error amplifier. DC/DC Q oscillates and VRL is
obtained so that the common driver negative power supply (VRL) and VRH are symmetric around VM.
12
Seiko Instruments Inc.
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
2. Step-up type switching regulators (DC/DC P and DC/DC U)
L
A
IOUT
D
VOUT
VIN
CONT
MC1
MC2
VOUT
COUT
Mode
control
∗
R1
M1
OSC
R2
*: In DC/DC P, R1 is a variable resistance controlled by the electric volume.
Figure 4 DC/DC P and DC/DC U
The fundamental equations {(1) to (7)} of the step-up type regulators are shown below (see Figure 4).
CONT pin voltage (VA) immediately after M1 is turned on (IL, which is the current that flows to L, is
zero):
VA = VS
..........................................................................................................................
(1)
(VS: Unsaturated voltage of M1)
Change in IL with time:
dIL VL VIN − VS
=
=
dt
L
L
......................................................................................................
(2)
Result of integrating the above equation (IL):
VIN − VS
IL =
•t
L
......................................................................................................
(3)
The current IL flows during time tON. This time (tON) is determined according to the oscillation frequency
of OSC.
Peak current (IPK) after tON:
VIN − VS
IPK =
• tON
L
......................................................................................................
(4)
The energy stored in L at this time is represented by 1/2⋅L(IPK)2.
Next, when M1 is turned off (tOFF), the energy stored in L is emitted through a diode, and a counter
voltage (VL) is generated.
Seiko Instruments Inc.
13
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
VL:
VL = (VOUT + VD ) − VIN
......................................................................................................
(5)
(VD: Diode forward voltage)
The CONT pin voltage rises by the voltage corresponding to VOUT + VD.
Change with time of current (IL) that flows to VOUT through a diode during time tOFF:
dIL VL VOUT + VD − VIN
=
=
dt
L
L
.................................................................................................
(6)
Result of integrating the above equation:
VOUT + VD − VIN
IL = IPK −
•t
L
..............................................................................................
(7)
During tON, the energy is stored in L and not transmitted to VOUT. When output current (IOUT) flows from
VOUT, the capacitor (COUT) energy is used. As a result, the COUT pin voltage decreases and reaches its
lowest value after time tON. When M1 is turned off, the energy stored in L is transmitted through the
diode to COUT, and the COUT pin voltage rises dramatically. VOUT is a time function that indicates the
maximum value (ripple voltage: VP-P) when the current flowing through the diode to VOUT matches the
load current IOUT.
This ripple voltage value is calculated below.
IOUT when the time from immediately after tON until VOUT reaches its highest level is set to t1:
VOUT + VD − VIN
IOUT = IPK −
• t1
L
L
+
−
V
OUT
V
D
V
IN
∴ t1 = (IPK − IOUT ) •
.........................................................................................
(8)
....................................................................................
(9)
Since IL=0 at time tOFF (when all inductor energy was emitted), the following is obtained from equation
(7):
L
tOFF
=
VOUT + VD − VIN
IPK
......................................................................................................
(10)
The following is obtained by substituting equation (10) into equation (9):
IOUT
t1 = tOFF −
• tOFF
IPK
14
......................................................................................................
Seiko Instruments Inc.
(11)
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
The amount of electric charge ∆Q1 charged in COUT during time t1:
∆Q1 = ∫0t1 IL dt = IPK • ∫0t1 dt −
= IPK • t1 −
VOUT + VD − VIN t1
• ∫0 t dt
L
VOUT + VD − VIN 1 2
•
t1
L
2
.........................................................................................
(12)
The following is obtained by substituting equation (9) into equation (12)
∆Q1 = IPK −
1
(IPK − IOUT ) • t1 = IPK + IOUT • t1 .........................................................................
2
2
(13)
The voltage rise (VP-P) due to ∆Q1 is as follows:
VP-P
=
1
∆Q1
IPK + IOUT
•
=
• t1
COUT COUT
2
...............................................................................
(14)
The following is obtained when the IOUT consumed during time t1 and RESR, which is the Electric Series
Resistance (ESR) of COUT, are taken into consideration:
VP-P
=
1
IOUT • t1
∆Q1
IPK + IOUT
IPK + IOUT
•
=
• RESR −
• t1 +
COUT COUT
2
2
COUT
...................................
(15)
The following is obtained when equation (11) is substituted into equation (15):
VP-P
=
(IPK − IOUT )2
2IPK
•
tOFF IPK + IOUT
+
• RESR
COUT
2
..................................................................
(16)
Effective ways to reduce the ripple voltage are to increase the capacitance of the capacitor connected
to the output pin and to reduce its ESR.
Note:
Although this IC has an on-chip soft-start circuit, a rush current flows because the output capacitor
(COUT) and load capacitance component are charged up via the coil and diode on power application.
Therefore, care must be taken.
Seiko Instruments Inc.
15
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
3. Inverter type switching regulator (DC/DC Q)
The fundamental equations of the inverter type regulator are shown below.
Point A voltage immediately after M1 is turned on (IL, which is the current that flows to L, is zero):
VA = VIN − VS
...................................
(17)
VIN
(VS: Unsaturated voltage of M1)
M1
IOUT
A
−VOUT
Di
L
Change in IL with time:
dIL VL VIN − VS
.............................
=
=
dt
L
L
COUT
OSC
(18)
Figure 5 Inverter Type Switching Regulator
Result of integrating the above equation (IL):
VIN − VS
IL =
• t .................................
L
(19)
The current IL flows during time tON. This time (tON) is determined according to the oscillation frequency
of OSC.
Peak current (IPK) after tON:
VIN − VS
IPK =
• tON
L
......................................................................................................
(20)
The energy stored in L at this time is represented by 1/2⋅L(IPK)2.
Next, when M1 is turned off, the energy stored in L is emitted through ground→capacitor→diode (Di),
and a counter voltage (VL) is generated at the same time.
VL:
VL = − (VOUT + VD )
......................................................................................................
(21)
(VD: Diode forward voltage)
Change with time of current (IL) that flows to −VOUT through a capacitor during time tOFF:
dIL VL VOUT + VD
=
=
dt
L
L
......................................................................................................
(22)
Result of integrating the above equation:
VOUT + VD
IL = IPK −
•t
L
16
......................................................................................................
Seiko Instruments Inc.
(23)
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
During tON, the energy is stored in L and not transmitted to −VOUT. When output current (IOUT) flows from
-VOUT, the capacitor (COUT) energy is used. As a result, the COUT pin voltage decreases and reaches its
lowest value after time tON. When M1 is turned off, the energy stored in L is transmitted through the
diode to COUT, and the COUT pin voltage rises dramatically. VOUT is a time function that indicates the
maximum value (ripple voltage: VP-P) when the current flowing through the diode to VOUT matches the
load current IOUT.
This ripple voltage value is calculated below.
IOUT when the time from immediately after tON until VOUT reaches its highest level is set to t1:
VOUT + VD
IOUT = IPK −
• t1 .....................................................................................................
L
(24)
L
................................................................................................
VOUT + VD
(25)
∴ t1 = (IPK − IOUT ) •
Since IL=0 at time tOFF (when all inductor energy was emitted), the following is obtained from equation
(23):
L
tOFF
=
VOUT + VD
IPK
......................................................................................................
(26)
The following is obtained by substituting equation (26) into equation (25):
IOUT
t1 = tOFF −
• tOFF
IPK
......................................................................................................
(27)
The amount of electric charge ∆Q1 charged in COUT during time t1:
∆Q1 = ∫0t1 IOUT dt = IPK • ∫0t1 dt −
= IPK • t1 −
VOUT + VD t1
• ∫0 t dt
L
VOUT + VD 1 2
•
t1 ......................................................................................................
L
2
(28)
The following is obtained by substituting equation (25) into equation (28)
∆Q1 = IPK −
1
(IPK − IOUT ) • t1 = IPK + IOUT • t1
2
2
............................................................................
(29)
The voltage rise (VP-P) due to ∆Q1 is as follows:
VP-P
=
∆Q1
COUT
=
1
COUT
•
IPK + IOUT
• t1
2
.................................................................................
Seiko Instruments Inc.
(30)
17
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
The following is obtained when the IOUT consumed during time t1 is taken into consideration:
VP-P
=
1
IOUT • t1
∆Q1
IPK + IOUT
•
=
.....................................................................
• t1 −
COUT COUT
2
COUT
(31)
The following is obtained when equation (27) is substituted into equation (31):
VP-P
18
=
(IPK − IOUT )2 •
2IPK
tOFF
COUT
.................................................................................................
Seiko Instruments Inc.
(32)
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
Operation Modes and Mode Control
The mode is switched among modes 1 to 3 according to the 2-bit input from the MC1 and MC2 pins and the
MC3 signal. The MC3 signal is not an input to a pin of this IC. It is a signal required for external part
control. This signal should be supplied from the LCD driver or LCD controller.
Since the MC1 and MC2 pins are not pulled up or pulled down internally, they should not be in a floating
state. Also, note that the current consumption in standby mode may exceed 1 µA if there is a potential
difference between the supply voltage of MC1 and MC2 and the supply voltage of the S-8335 Series IC.
MC1
MC2
MC3*
L
L
H
Operation Mode
L
H
L
Mode 2 (Icon mode)
H
X
L
Mode 3 (Standby mode)
Mode 1 (Normal operation)
Remark: L: Low level, H: High level, X: Don't care
*
MC3 is a signal that is the input to an external switch to forcibly discharge a capacitor in modes 2
and 3.
1. Normal operation mode (MC1=L, MC2=L, MC3=H)
Step-up operation is performed.
2. Icon mode (MC1=L, MC2=H, MC3=L)
Only the reference voltage circuit and regulator S operate. The regulator S output VREGSO can be set
arbitrarily in the range from 1.0 to 2.2 V by using external resistors RS1 and RS2. VREGSO can be used
as the icon voltage. Use an RS1 value that matches the temperature characteristics of the panel by
combining a series or parallel resistor with a thermistor as necessary. See the section on regulator S
for information about the output voltage characteristics of regulator S when the output current is drawn.
3. Standby mode (MC1=H, MC3=L)
The operation of internal circuits is shut down. The current consumption does not exceed 1 µA.
When the MC1 pin is set high ("H" level), the operation of all internal circuits stops, and the current
consumption is dramatically reduced. At the same time, the VOUT1, VXO, VYO, VREGSO, and
VREGTO pins are each short-circuited to VSS by on-chip Nch transistors. (However, data that was
written to the register of the electric volume part is retained if a voltage of at least 2 V is applied
between the VBAT and VSS pins.) Since current flows at this time from the VOUT1 pin to VSS through a
coil and a diode at the input side, a switch for shutting down the current is required.
Figure 6 shows a sample circuit that uses NEC’s 2SJ356 (Pch MOSFET) as the current breaker switch.
In this sample circuit, the small signal transistor E (Nch MOSFET) is used to turn 2SJ356 on or off by
inputting the control signal MC3 to the gate of transistor E.
An invalid current flowing to resistor RA1 during a step-up operation may affect efficiency. Resistor
RA1 should be set to a high resistance value to reduce current. However, if the RA1 resistance value is
set too high, a voltage drop across resistor RA1 will occur due to the off-leak current of the small signal
transistor E, and the 2SJ356 current breaker switch may not turn off. Therefore, care must be taken.
Note:
The efficiency characteristics shown in the reference data, which were measured without a current
breaker switch, differ from the efficiency of this sample circuit.
Seiko Instruments Inc.
19
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
SBD
L1
2SJ356
A
D1
CONT1
VOUT1
RESET
RA2:
150 kΩ
RA1:
470 kΩ
VBAT
MC1
CL1
MC2
E
VSS
MC3
Figure 6 Sample Circuit in Which 2SJ356 is Used
When mode 3 (standby mode) is canceled, the mode returns to the one that was in effect before switching to standby mode. For
example, if the IC entered mode 3 from mode 1, it will return to mode 1 when mode 3 is canceled.
Note 1:
For example, when the applied voltage to MC1 and MC2 is
3.0 V and the power supply voltage of the S-8335 Series is
5.0 V, the current consumption in standby mode rises to
approximately 2.5 µA at 25°C (typ.) (see Figure 7). The
reason this occurs is that a penetrating current flows in
CMOS logic circuits because the potential of input signals
MC1 and MC2 (3.0 V) is lower than the internal logic power
supply voltage (5.0 V).
3
Standby Current [µA]
If there is a potential difference between the applied voltage
to MC1 and MC2 and the power supply voltage of the S8335 Series, the current consumption in standby mode may
exceed 1 µA.
2.5
VMC1 = 3.0 V
2
1.5
1
0.5
0
2.0
2.5
3.0
3.5
4.0
VBAT [V]
4.5
5.0
Figure 7 Standby Mode Current Characteristics
Therefore, use this IC in such a way that no potential
difference occurs between the applied voltage to MC1 and
MC2 and the power supply voltage of the S-8335 Series.
MC1 (or MC2)
Note 2:
A penetrating current from VBAT to VSS flows when the mode
is switched. When MC1 (or MC2) = "H" and MC3 = "H", a
current of approximately 6 mA flows from the VBAT pin
through the coil L1, diode D1, and transistor A because the
VOUT1 pin is short-circuited to GND level.
MC3
Also, when MC1 (or MC2) = "L" and MC3 = "L", VRL and
GND are short-circuited via
transistor G, and a current of approximately 150 mA flows.
20
To reduce the penetrating current, the MC1 (or MC2) and
MC3 signals should both be switched at the same time when
modes are switched. If this cannot be done, avoid a state in
which the MC1 (or MC2) and MC3 signals are both low ("L"
level) at the same time in order to reduce the penetrating
current (see Figure 8).
Seiko Instruments Inc.
Normal mode
Standby mode
(or icon mode)
Normal mode
Figure 8 Mode Switching
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
Electric volume
VDIN
VCLK
6-bit shift
register
VDIN
D5
D4
D3
D2
D1
(MSB)
D0
(LSB)
VCLK
RESET
VSTR_B
6-bit latch
VSTR_B
Hold
Read
Reset
VOUT
Electric
volume
Hold
min. value
Setting
value
VOUT
Figure 9 Block Diagram and Clock Timing of Electric Volume Part
VDIN:
This is the data input pin to the electric volume.
"Data 1" is an input for the “H” level, and "data 0" is an input for the "L" level.
(A high impedance state is prohibited.) When no data is sent, keep VDIN at the "L" level.
VCLK:
This is the clock input pin to the electric
volume.
The data of the VDIN pin is fetched to the
shift register at the clock rising edge.
When a clock with more than six bits data
is input, the data that had been read is
sequentially shifted at each clock pulse,
and the last six bits of data become
effective.
VSTR_B: This is the strobe signal input pin.
When the strobe signal goes low (set to "L"
level), the shift register contents are
fetched to the latch. The data that is
fetched to the latch is sent directly to the
electric volume, and consequently the
output voltage changes. When the strobe
signal goes high (set to "H" level), the latch
data is held.
Output
voltage
(V)
±1/2 LSB
±1/2
LSB
0
1
31 32
62 63
Electric
volume
data
(DEC)
Figure 10 Linearity Error
Seiko Instruments Inc.
21
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
The electric volume has 6-bit resolution. The integral and differential linearity errors are ±0.5LSB. For
example, if you want the VRH output voltage range to vary between 8.91 and 16.59 V, you can obtain a
linearity precision of ±61 mV by selecting the S-8335A240FT.
Since the register contents are undefined when the power is turned on, they must be reset. Even if the
MC1 pin or MC2 pin is set high ("H" level) and the MC3 signal is set low ("L" level) and the step-up
operation stops, the electric volume register contents are retained if a voltage of at least 2 V is applied
between the VBAT and VSS pins. Register “WRITE” and “RESET” operations are also available in this
state.
The register is initialized to “000000” and the output voltage is set to its minimum value by setting VCLK =
"H" and VSTR_B = "L".
Turn on the power with MCI = “H” and MC3 = “L”. Then initialize the register contents by setting VCLK =
"H" and VSTR_B="L" and begin the step-up operation by switching the MC1 and MC2 pins low ("L" level)
and the MC3 signal high ("H" level).
Caution:
If a step-up operation is started without initializing the data in the register after turning on the
power, the maximum output voltage may appear at the VOUT pins and connected devices or
instruments may be damaged. It is recommended to connect a pull-down resistor between VSS
and the external part pins that the MC3 signal enters and to connect a pull-up resistor between
the MC1 pin and VBAT.
Note:
22
3
Standby current [µA]
If there is a potential difference between
the applied voltage to VDIN, VCLK, and
VSTR_B and the power supply voltage of
the
S-8335
Series,
the
current
consumption in standby mode may exceed
1 µA. For example, when the applied
voltage to VDIN, VCLK, and VSTR_B is
3.0 V and the power supply voltage of the
S-8335 Series is 5.0 V, the current
consumption in standby mode rises to
approximately 2.5 µA at 25°C (typ.) (see
Figure 11). The reason this occurs is that
a penetrating current flows in the CMOS
logic circuits because the potential of input
signals VDIN, VCLK, and VSTR_B (3.0 V)
is lower than the internal logic power
supply voltage (5.0 V). A similar situation
occurs for the power supply voltage of
MC1 and MC2 (see Note in the Mode
Control section).
2.5
VDIN = 3.0 V
2
1.5
1
0.5
0
2.0
2.5
3.0
3.5
4.0
VBAT [V]
4.5
5.0
Figure 11 Standby Mode Current Characteristics
Seiko Instruments Inc.
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
The power supply voltage of OP amplifier X is
generated using DC/DC U so that it is approximately
1.05 times larger than the output voltage of OP
amplifier X. Since the difference between the power
supply voltage and output voltage is kept small, the
power loss is extremely small and efficiency is
increased. Figure 12 shows the output voltage of OP
amplifier X when source current is drawn.
VXO [V]
OP amplifier X
4
3.5
3
2.5
2
1.5
1 240 dot,25°C
0.5 VBAT =3.0V
0
EV=MIN
EV=MID
EV=MAX
500
1000
1500
2000
SOURCE CURRENT, IOUTX[µA]
Figure 12 OP Amplifier X Output Voltage
OP amplifier Y
VBAT is used for the power supply voltage of OP amplifier Y. Figures 13 and 14 show the output voltage of
OP amplifier Y when source current and sink current are drawn, respectively.
1.5
1.5
1
0.5
0
EV=MIN
EV=MID
EV=MAX
240 dot,25 °C
VBAT=3.0V
500
1000
SOURCE CURRENT,
1500
VYO [V]
2
VYO [V]
2
1
2000
0
−500
IOUTY [µA]
Figure 13 VYO Pin Source Current Characteristics
EV=MIN
EV=MID
EV=MAX
0.5 240 dot,25 °C
VBAT=3.0V
−1000
SINK CURRENT,
−1500
−2000
IOUTY [µA]
Figure 14 VYO Pin Sink Current Characteristics
VBAT is used for the power supply voltage of the
regulator S part. The regulator S output VREGSO can
be set arbitrarily in the range from 1.0 to 2.2 V by
using external resistor RS1 and RS2. VREGSO can be
used as the icon voltage. Use an RS1 value that
matches the temperature characteristics of the panel
by combining a series or parallel resistor with a
thermistor as necessary.
VREGSO [V]
Regulator S Part
1.6
1.58
1.56
1.54
1.52
1.5
1.48
1.46
Also, CRS1 is a capacitor for preventing oscillation.
It is required only when the regulator oscillates.
Adjust the CRS1 value when the RS1 and RS2
values are changed.
Using the actual device,
confirm that the regulator does not oscillate. Figure
15 shows the voltage VREGSO when current is drawn.
Seiko Instruments Inc.
VBAT=2.4V
VBAT=3.0V
VBAT=5.0V
0
500
1000
1500
2000
IOUT [µ A]
Figure 15 VREGSO Characteristics
23
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
Regulator T Part
VREGTO [V]
VBAT is used for the power supply voltage of the
regulator T part. The regulator T output VREGTO can
be set by using external resistance RT1 and RT2.
Set VREGTO to match the voltage range that is to be
used.
The common-driver voltage VRH_max is obtained by
VREGTO × 7.136, and VRH_min is obtained by VREGTO ×
3.832. Figure 16 shows the voltage VREGTO when
current is drawn.
2.35
2.3
2.25
2.2
2.15
2.1
2.05
2
VBAT=2.4V
VBAT=3.0V
VBAT=5.0V
0
500
1000
1500
2000
IOUT [µ A]
Figure 16 VREGTO Characteristics
Power Supply Rising Edge Sequence
The power supply rising edge sequence is VRH, VCH, VM, VRL. The falling edge sequence is VRL, VM, VCH,
VRH. (See Figure 17.)
VRH : 2 V/div
VCH : 2 V/div
VM : 2 V/div
VRL : 5 V/div
t : 5 ms/div
VRH
V
VCH
VM
VRL
t
Figure 17 Rising and Falling Edge Sequences
Soft Start
The soft-start function blunts the rising edge of the reference voltage VREGTO by using an external capacitor
CSS and an internal resistor so that the rush current can be reduced to some degree corresponding to this
moderated ascent. However, note that this is not a complete soft start because the switching regulators of
the S-8335 Series use PFM control.
24
Seiko Instruments Inc.
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
Selection of External Parts
1. Inductor
The inductance value significantly affects the maximum output current IOUT and efficiency η (EFFI).
Figure 18 shows graphs of the dependency of IOUT and EFFI for the S-8335 Series on the inductance
value L.
DC-DC Q ( VOUT=16.6 V, VBAT=3.0 V )
DC-DC P (VOUT = 16.6 V, VBAT = 3.0 V)
EFFIP
IOUT
IOUT
100
IOUT
EFFIQ
IOUT
EFFIP
L value (µH)
150
EFFIQ
100
180
L value (µH)
Recommended
range
Recommended
range
DC-DC U (VOUT = 3.99 V, VBAT = 3.0 V )
EFFIU
IOUT
IOUT
100
EFFIU
150
180
L value (µH)
Recommended
range
Figure 18 Dependency of IOUT and EFFI on Inductance Value L
As the L value decreases, the peak current IPK increases, and IOUT reaches its maximum at a certain L
value. If the L value decreases further, the current driving capability of the switching transistor becomes
insufficient, and IOUT is reduced.
Also, as the L value increases, the power loss due to IPK at the switching transistor decreases, and the
efficiency reaches its maximum at a certain L value. If the L value increases further, the power loss due
to the series resistance of the coil increases, and efficiency is reduced.
The recommended inductance value is 100 to 150 µH for DC/DC P and 100 to 180 µH for DC/DC Q
and DC/DC U.
Seiko Instruments Inc.
25
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
When you select inductors, pay attention to the permissible current of the inductors. If a current that
exceeds the permissible current flows in the inductor, magnetic saturation will occur in the inductor.
This may cause a significant decrease in efficiency and may damage the IC due to excessive current.
Therefore, select inductors so that the peak current IPK does not exceed the permissible current. The
peak current IPK in non-continuous mode is given by the following equation.
IPK =
2IOUT • ( VOUT + VD − VIN )
fOSC • L
(A)
......................................................................................
(33)
where fOSC is the oscillation frequency. VD is approximately 0.4 V.
For example, assume that output voltage VOUT = 16.6 V, with load current IOUT = 2mA, using
S-8335A240FT with the input voltage VIN = 3 V and fOSC = 100 kHz. If 150 µH is selected for the L
value, then IPK = 61 mA from equation (33). Therefore, an inductor having a permissible current of at
least 61 mA at an L value of 150 µH should be selected.
2. Diode
An off-chip diode must satisfy the following conditions.
•
•
•
•
Low forward voltage:
VF < 0.3 V
Fast switching speed:
500 ns max.
Reverse breakdown voltage: VOUT+VF or more
Rated current:
IPK or more
3. Capacitors (CVBAT, CL)
The input capacitor (CVBAT) can improve efficiency by decreasing the power supply impedance and
stabilizing the input current. Select the capacitor value according to the impedance of the power supply
used. Connect a capacitor of at least 1 µF to each of the two power supply pins.
For the output capacitor (CL), use a capacitor having a small Electric Series Resistance (ESR) and
large capacitance to stabilize the ripple voltage. Standard capacitor values are at least 2.2 µF for CL1
and CL2 and at least 10 µF for CL3. In particular, a tantalum electrolytic capacitor having excellent low
temperature characteristics and low leakage current characteristics should be used. A capacitor having
a large capacitance produces more stable output and leads to higher efficiency.
26
Seiko Instruments Inc.
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
Standard Circuits
D3
L3
L1
D1
CL3
A
VRH
CL1
12
1
6
16
2
RESET
CVBAT2
3
24
VOUT3
CONT3
VSTR_B
4
21
Electric
volume
DC/DC P
VBAT
VCLK
E
MC3
VDIN
CVBAT1
RA2
VOUT1
CONT1
RA1
DC/DC U
PFM
control
circuit
PFM
control
circuit
5
CR1
17
23
MC2
CMC2
PFM
control
circuit
Mode
control
circuit
CMC1
22
14
20
VQERR
VREFU
CREFU
Reference
voltage
generation
circuit
op-amp X
Oscillator
REG S
19
VDDX
18
VCH
CL4
13
VM
CL5
VXO
REG T
VYO
VREGSF VREGSO VREGTF VREGTO
11
R2
CR2
DC/DC Q
MC1
R1
10
9
CL6
8
CL7
RS2
: small current VSS,
15
CSS
CRS1 VICON
RS1
D2
F
RT1
op-amp Y
EXT2
7
L2
CL2
VRL
G
CRT1
RT2
RA3
VBAT
C
D
MC3
: large current VSS
Figure 19 Standard Circuits
Except for op-amp X, all of the power for the internal circuits of the S-8335 Series is supplied by the VBAT
pin.
Seiko Instruments Inc.
27
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
Pattern Diagram
In general, the switching regulator is significantly affected by the circuit board wiring. The following figure
shows a sample pattern diagram for which the effect of the circuit board wiring is small.
55 mm
59 mm
Figure 20 Pattern Diagram
Note the following points when creating a pattern diagram.
• There are two VSS lines (connected inside the IC).
a) VSS (pin No. 5): Large current GND
b) VSS (pin No. 17): Small current (analog) + middle current GND
• Arrange the VSS line and capacitors first. CVBAT, CL1, CL2, and CL3 are particularly important. Draw
the VSS line as wide as possible.
• Basically, make the GND part of the circuit board as broad as possible and keep the impedance low.
• There are two VBAT lines (not connected inside the IC).
a) VBAT (pin No. 12): Reference (low noise)
b) VBAT (pin No. 16): All others (semi-low noise)
• Connect CL3 at both pin No. 19 (VDDX) and pin No. 21 (VOUT3) if possible (for example, connect
6.8 µF at each pin).
• Do not use through holes at locations for connecting CL1 to CL3.
• Increasing CL1 makes the output more stable. If the DC/DC P output fluctuates due to ripple, and this
causes VQERR to frequently exceed the DC/DC Q error amplifier threshold value, then DC/DC Q
oscillates more than necessary and the DC/DC Q efficiency will decrease. Therefore, stabilizing the
DC/DC P output will also improve DC/DC Q efficiency.
28
Seiko Instruments Inc.
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
Application Circuit
D3
L3
L1
D1
CL3
A
CL1
12
1
6
2
3
4
24
21
VDDX
VOUT3
CONT3
VSTR_B
VCLK
MC3
VDIN
CVBAT1
RA2
VOUT1
VBAT
CONT1
RA1
19
16 VBAT
CVBAT2
CR1
R1
CR2
R2
VQERR 14
VBAT
5
VSS
VREFU 20
S-8335
CREFU
17 VSS
MC1
CL4
CMC1
MC2
CMC2
22
VCH
Segment
driver
VM
VCL
VXO 18
23 MC1
VYO 13
MC2
CL5
VREGSF VREGSO VREGTF VREGTO
11
10
9
CL6
8
CL7
EXT2
7
CSS
CRS1 VICON
RS1
RS2
: small current VSS,
15
F
RT1
VM
D2
L2 CL2
G
CRT1
RT2
RA3
VBAT
C
D
VRL VRH
Common
driver
MC3
: large current VSS
Figure 21 Application Circuit Example
Seiko Instruments Inc.
29
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
Precautions
• Mount external capacitors, diodes, coils, and other components as close as possible to the IC.
• The RS1, RS2, RT1, and RT2 values of the recommended peripheral parts are for VICON = 1.6 V. If a
VICON value other than 1.6 V is used, the resistance values should be changed. The output voltage
precision does not include external resistance dispersion.
• Characteristic ripple voltage and spike noise occur at the switching regulator. Since these are
significantly affected by the coil and capacitor that are used, evaluate them using actual devices when
the circuit is designed.
• CR1 and CR2 contribute to the stability of the VQERR pin potential and increase the efficiency of
switching regulator Q. Although a capacitance value in the range from 1000 pF to 0.01 µF is
recommended for CR1 and CR2, you should evaluate this value using an actual device.
Power dissipation PD (mW)
• Make sure that the operating ambient temperature range of this IC is not exceeded due to switching
transistor power dissipation (particularly at high temperature).
1000
800
600
400
200
0
50
100
150
Ambient temperature TOPR (°C)
Figure 22 Power Dissipation of 24-pin TSSOP Package (Unmounted)
• Arrange parts so that the line to the VSS pin (indicated by the bold line in Figure 23) is as short as
possible. If this line has resistance and inductance components, the VSS potential of the IC will
fluctuate due to the switching current. If a potential difference is produced between the VSS of the CPU
and the VSS of the IC, a malfunction may occur in the interface, and the electric volume may be reset.
VIN
CONT
VDIN
VCLK
CPU
VSS
S-8335
VSTR_B
VSS
Figure 23 VSS Line
30
Seiko Instruments Inc.
VOUT
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
• When switching the output voltage by the electric volume, the soft start does not function. Note that an
overshoot will occur when the output voltage increases by a large amount.
• When the internal impedance of the power supply (VBAT) is large, the S-8335 Series may not start up.
Make sure that the internal impedance of the power supply used is sufficiently small when using this IC.
• Make sure that the potential of the VOUT1 pin does not exceed 20 V, which is the absolute maximum
rating, when using this IC.
• Make the capacitance of VDIN, VCLK, and VSTR_B large enough to prevent noise and malfunctions.
• Seiko Instruments Inc. shall bear no responsibility for any patent infringement by a product that includes
an IC manufactured by Seiko Instruments Inc. in relation to the method of using this IC in that product,
the product specifications, or the destination country.
Seiko Instruments Inc.
31
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
Characteristic Curves
1. Common characteristics (Unless otherwise specified, these graphs show typical data for TOPR = 25°C.)
Current consumption
(for mode 1 when oscillation is stopped)
Current consumption
(for mode 1 with full oscillation)
41
160
140
40
IMC11 [µA]
IMC12 [µA]
39
38
37
36
35
1
2
3
4
5
120
100
80
60
40
20
0
6
VBAT [V]
3
14
3
12
2.5
10
2
8
6
4
6
4
5
6
5
6
1.5
1
1
2
3
4
5
0
6
1
2
3
VBAT [V]
VBAT [V]
ISSX [µA]
8.95
8.9
8.85
8.8
8.75
8.7
8.65
8.6
8.55
VXO pin sink current
IVXOL [µA]
OP amplifier X part current consumption
1
2
3
4
5
6
0.72
0.71
0.7
0.69
0.68
0.67
0.66
0.65
0.64
0.63
0.62
1
VBAT [V]
0.66
0.65
0.64
0.63
0.62
0.61
0.6
0.59
1
2
3
2
3
4
VBAT [V]
VYO pin sink current
IVYOL [µA]
5
0.5
2
4
5
6
VBAT [V]
32
4
Current consumption (mode 3)
IMC3 [µA]
IMC2 [µA]
2
VBAT [V]
Current consumption (mode 2)
0
1
Seiko Instruments Inc.
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
DC/DC P part switching current
DC/DC P part switching transistor leakage current
140
0.02
0.016
100
ISWQP [µA]
ISWP [mA]
120
80
60
40
0.008
0.004
20
0
0.012
1
2
3
4
5
0
6
1
2
3
VBAT [V]
DC/DC Q part comparator offset voltage
IEXT2H [mA]
VQEROF [mV]
−0.5
5
6
4
5
6
4
5
6
8
6
4
2
1
2
3
VBAT [V]
4
5
0
6
EXT2 pin current (IEXT2L)
1
2
3
VBAT [V]
DC/DC U part switching current
140
120
ISWU [mA]
IEXT2L [mA]
4
10
−1
100
80
60
40
20
0
1
2
3
VBAT [V]
4
5
6
2
3
VOUT3 pin off current
1
0.008
0.8
IVOUT3L [µA]
0.01
0.006
0.004
0.6
0.4
0.2
0.002
0
1
VBAT [V]
DC/DC U part switching transistor leakage current
ISWQU [µA]
6
12
−1.5
18
16
14
12
10
8
6
4
2
0
5
EXT2 pin current (IEXT2H)
−2
0
4
VBAT [V]
1
2
3
4
5
6
0
1
VBAT [V]
2
3
VBAT [V]
Seiko Instruments Inc.
33
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
Regulator S part output voltage (vs. IOUT)
1.6
1.6
1.5995
1.58
1.599
1.56
VREGSO [V]
VREGSO [V]
Regulator S part output voltage (vs. VBAT)
1.5985
1.598
1.52
VBAT=2.4V
VBAT=3.0V
VBAT=5.0V
1.5
1.5975
1.597
1.54
1.48
1
2
3
4
5
1.46
6
0
500
1000
IOUT [µA]
VBAT [V]
VREGSO pin sink current
1
IVREGTOL [mA]
IVREGSOL [mA]
0.8
0.6
0.4
0.2
1
2
3
4
5
0
6
1
2
3
MC1, MC2 pin high level voltage
VCL [V]
VCH [V]
4
5
6
0.598
1
0.8
0.6
0.4
0.596
0.594
0.592
0.2
1
2
3
4
5
6
VBAT [V]
0.59
1
20
18
16
14
12
1
2
3
2
3
VBAT [V]
Soft start time
tSS [ms]
6
0.6
1.2
4
5
6
VBAT [V]
34
5
MC1, MC2 pin low level voltage
1.4
10
4
VBAT [V]
VBAT [V]
0
2000
VREGTO pin sink current
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
1500
Seiko Instruments Inc.
Rev.6.0_01
2.
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
S-8335A240FT (1/240 duty. Unless otherwise specified, these graphs show typical data for TOPR =
25°C.)
4
3.5
3
2.5
2
1.5
1
0.5
0
OP amplifier X part output voltage (VBAT = 3.0 V)
4
3.5
VXO [V]
VXO [V]
OP amplifier X part output voltage (VBAT = 2.4 V)
EV=MIN
EV=MID
EV=MAX
0
500
1000
1500
2000
3
2.5
2
1.5
1
0.5
0
EV=MIN
EV=MID
EV=MAX
0
SOURCE CURRENT, IOUTX [µA]
OP amplifier Y part output voltage
(vs. source current, VBAT = 2.4 V)
VYO [V]
VYO [V]
1.5
1
EV=MIN
EV=MID
EV=MAX
0.5
0
500
1000
1500
2000
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
OP amplifier Y part output voltage
(vs. sink current, VBAT = 2.4 V)
VYO [V]
VYO [V]
1.5
1
EV=MIN
EV=MID
EV=MAX
0
−500
−1000
2000
EV=MID
EV=MAX
0
500
1000
SOURCE CURRENT,
1500
IOUTY [µA]
2000
OP amplifier Y part output voltage
(vs. sink current, VBAT = 3.0 V)
2
0
1500
IOUTX [µA]
EV=MIN
SOURCE CURRENT, IOUTY [µA]
0.5
1000
OP amplifier Y part output voltage
(vs. source current, VBAT = 3.0 V)
2
0
500
SOURCE CURRENT,
−1500
−2000
SINK CURRENT, IOUTY [µA]
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
EV=MIN
EV=MID
EV=MAX
0
−500
−1000
−1500
SINK CURRENT, IOUTY [µA]
−2000
Regulator T part output voltage
2.35
VREGTO [V]
2.3
2.25
2.2
2.15
VBAT=2.4V
VBAT=3.0V
VBAT=5.0V
2.1
2.05
2
0
500
1000
IOUT [µA]
1500
2000
Seiko Instruments Inc.
35
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
VOUT1 [V]
DC/DC P part output voltage
18
16
14
12
10
8
6
4
2
0
VBAT=2.4V
VBAT=3V
VBAT=5V
0
20
40
EV Point
60
80
DC/DC P part output efficiency (VBAT = 2.4 V)
DC/DC P part output ripple voltage
(VBAT = 2.4 V, reference value)
70
60
50
40
30
20
10
0
30
25
Ripple [mV]
EFFIP [%]
80
EV=MIN
EV=MID
500
1000
IOUT [µA]
1500
EFFIP[%]
Ripple [mV]
EV=MID
EV=MAX
500
1000
IOUT [µA]
1500
2000
DC/DC P part output efficiency (VBAT = 5.0 V)
Ripple [mV]
EFFIP [%]
60
EV=MIN
EV=MID
EV=MAX
0
0
36
500
1000
IOUT [µA]
1500
0
500
1000
IOUT [µA]
1500
2000
50
45
40
35
30
25
20
15
10
5
0
EV=MIN
EV=MID
EV=MAX
500
1000
IOUT [µA]
1500
2000
DC/DC P part output ripple voltage
(VBAT = 5.0 V, reference value)
80
20
EV=MAX
0
100
40
EV=MID
DC/DC P part output ripple voltage
(VBAT = 3.0 V, reference value)
EV=MIN
0
EV=MIN
10
0
2000
DC/DC P part output efficiency (VBAT = 3.0 V)
90
80
70
60
50
40
30
20
10
0
15
5
EV=MAX
0
20
2000
180
160
140
120
100
80
60
40
20
0
EV=MIN
EV=MID
EV=MAX
0
Seiko Instruments Inc.
500
1000
IOUT [µA]
1500
2000
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
VOUT2 [V]
DC/DC Q part output voltage
-13
-12
-11
-10
-9
-8
-7
-6
-5
-4
VBAT=3V
0
20
40
EV Point
60
80
DC/DC Q part output efficiency (VBAT = 2.4 V)
DC/DC Q part output ripple voltage
(VBAT = 2.4 V, reference value)
70
50
40
50
Ripple [mV]
EFFIQ [%]
60
40
30
EV=MIN
20
EV=MID
10
EV=MAX
30
20
EV=MIN
EV=MID
10
0
EV=MAX
0
0
500
1000
1500
2000
0
500
IOUT [µA]
DC/DC Q part output efficiency (VBAT = 3.0 V)
50
Ripple [mV]
EFFIQ[%]
60
40
30
EV=MIN
20
EV=MID
10
EV=MAX
0
500
1000
1500
80
70
60
50
40
30
20
10
0
2000
EV=MID
EV=MAX
0
500
1000
1500
2000
IOUT [µA]
DC/DC Q part output efficiency (VBAT = 5.0 V)
DC/DC Q part output ripple voltage
(VBAT = 5.0 V, reference value)
350
300
Ripple [mV]
EFFIQ[%]
2000
EV=MIN
IOUT [µA]
90
80
70
60
50
40
30
20
10
0
1500
DC/DC Q part output ripple voltage
(VBAT = 3.0 V, reference value)
70
0
1000
IOUT [µA]
EV=MIN
EV=MID
EV=MAX
0
500
1000
1500
2000
250
200
150
100
EV=MIN
50
EV=MID
EV=MAX
0
0
IOUT [µA]
500
1000
1500
2000
IOUT [µA]
Seiko Instruments Inc.
37
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
4
3.5
3
2.5
2
1.5
1
0.5
0
DC/DC U part output voltage (VBAT = 3.0 V)
VOUT3 [V]
VOUT3 [V]
DC/DC U part output voltage (VBAT = 2.4 V)
EV=MIN
EV=MID
EV=MAX
0
200
400
600
IOUTX [µA]
800
1000
5
4
4
3
EV=MIN
EV=MID
1
EV=MID
EV=MAX
EV=MAX
800
1000
3
2
VBAT=2.4V
VBAT=3V
VBAT=5V
0
0
200
400
600
IOUTX [µA]
800
1000
DC/DC U part output voltage (EV = Mid.)
0
4
4
VOUT3 [V]
5
3
2
200
400
600
IOUTX [µA]
800
1000
DC/DC U part output voltage (EV = Max.)
5
VBAT=2.4V
VBAT=3V
VBAT=5V
1
3
2
VBAT=2.4V
VBAT=3V
VBAT=5V
1
0
0
0
200
400
600
IOUTX [µA]
800
1000
0
DC/DC U part output voltage (VBAT = 3.0 V, VREFU = 2.90 V)
3.06
3.055
VOUT3 [V]
400
600
IOUTX [µA]
1
0
3.05
3.045
3.04
0
38
200
DC/DC U part output voltage (EV = Min.)
5
2
EV=MIN
0
VOUT3 [V]
VOUT3 [V]
DC/DC U part output voltage (VBAT = 5.0 V)
VOUT3 [V]
4
3.5
3
2.5
2
1.5
1
0.5
0
20
40
EV Point
60
80
Seiko Instruments Inc.
200
400
600
IOUTX [µA]
800
1000
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
80
70
60
50
40
30
20
10
0
DC/DC U part output ripple voltage
(VBAT = 2.4 V, reference value)
Ripple [mV]
EFFIU[%]
DC/DC U part output efficiency (VBAT = 2.4 V)
EV=MIN
EV=MID
EV=MAX
0
500
1000
IOUT [µA]
1500
2000
DC/DC U part output efficiency (VBAT = 3.0 V)
Ripple [mV]
EFFIU[%]
EV=MIN
EV=MID
EV=MAX
20
0
0
500
1000
IOUT [µA]
1500
Ripple [mV]
EFFIU[%]
EV=MID
EV=MAX
20
0
0
500
1000
IOUT [µA]
1500
1000
IOUT [µA]
1500
2000
EV=MIN
EV=MID
EV=MAX
500
1000
IOUT [µA]
1500
2000
DC/DC U part output ripple voltage
(VBAT = 5.0 V, reference value)
80
EV=MIN
500
40
35
30
25
20
15
10
5
0
0
100
40
EV=MAX
2000
DC/DC U part output efficiency (VBAT = 5.0 V)
60
EV=MID
DC/DC U part output ripple voltage
(VBAT = 3.0 V, reference value)
80
40
EV=MIN
0
100
60
16
14
12
10
8
6
4
2
0
2000
4
3.5
3
2.5
2
1.5
1
0.5
0
EV=MIN
EV=MID
EV=MAX
0
Seiko Instruments Inc.
500
1000
IOUT [µA]
1500
2000
39
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
S-8335A200FT (1/200 duty. Unless otherwise specified, these graphs show typical data for TOPR =
25°C.)
3.
DC/DC P part output voltage
DC/DC Q part output voltage
16
12
VOUT2 [V]
VOUT1 [V]
14
10
VBAT=3V
8
6
0
20
40
60
-12
-11
-10
-9
-8
-7
-6
-5
-4
80
VBAT=3V
0
20
EV Point
DC/DC U part output voltage (VREFU = 2.91 V)
VREFU=2.91V
VXO [V]
VOUT3 [V]
4.5
4
VBAT=3V
VBAT=5V
3
0
20
40
60
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
EV=MID
EV=MAX
0
80
2
2
1.5
1.5
VYO [V]
VYO [V]
2.5
EV=MIN
EV=MAX
500
1000
SOURCE CURRENT,
1500
1
2000
EV=MAX
0
0
IOUTY [µA]
VREGTO [V]
2.1
2.08
2.06
2.04
2.02
2
1000
1500
2000
IOUT [µA]
40
−500
−1000
SINK CURRENT,
2.12
500
2000
EV=MID
Regulator T part output voltage (VBAT = 3.0 V)
0
1500
IOUTX [µA]
EV=MIN
0.5
EV=MID
0
1000
OP amplifier Y part output voltage
(vs. sink current, VBAT = 3.0 V)
2.5
0
500
SOURCE CURRENT,
OP amplifier Y part output voltage
(vs. source current, VBAT = 3.0 V)
0.5
80
EV=MIN
EV Point
1
60
OP amplifier X part output voltage
(vs. source current, VBAT = 3.0 V)
5
3.5
40
EV Point
Seiko Instruments Inc.
−1500
IOUTY [µA]
−2000
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
DC/DC P part output ripple voltage
(VBAT = 3.0 V, reference value)
70
90
80
70
60
50
40
30
20
10
0
60
Ripple [mV]
EFFIP [%]
DC/DC P part output efficiency (VBAT = 3.0 V)
EV=MIN
EV=MID
EV=MAX
50
40
30
EV=MIN
20
EV=MID
10
EV=MAX
0
0
500
1000
1500
0
2000
500
IOUT [µA]
1500
2000
DC/DC Q part output ripple voltage
(VBAT = 3.0 V, reference value)
120
80
70
60
50
40
30
20
10
0
100
Ripple [mV]
EFFIQ [%]
DC/DC Q part output efficiency (VBAT = 3.0 V)
EV=MIN
EV=MID
80
60
40
EV=MIN
EV=MID
EV=MAX
20
EV=MAX
0
0
500
1000
IOUT [µA]
1500
0
2000
DC/DC U part output efficiency (VBAT = 3.0 V)
500
1000
IOUT [µA]
1500
2000
DC/DC U part output ripple voltage
(VBAT = 3.0 V, reference value)
60
100
50
Ripple [mV]
80
EFFIU[%]
1000
IOUT [µA]
60
EV=MIN
40
EV=MID
20
40
EV=MIN
EV=MID
EV=MAX
30
20
10
EV=MAX
0
0
0
500
1000
IOUT [µA]
1500
2000
0
500
1000
1500
2000
IOUT [µA]
Seiko Instruments Inc.
41
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
4.
S-8335A160FT (1/160 duty. Unless otherwise specified, these graphs show typical data for TOPR =
25°C.)
DC/DC Q part output voltage
14
13
-11
12
11
10
9
-9
-10
VOUT2 [V]
VOUT1 [V]
DC/DC P part output voltage
VBAT=3V
8
7
6
-6
-4
20
40
EV Point
60
0
80
DC/DC U part output voltage (VREFU = 2.906 V)
VXO [V]
VREFU=2.906V
VBAT=3V
4
VBAT=5V
3.5
3
2.5
2
1.5
60
80
EV=MIN
1
0.5
0
3
0
20
40
EV Point
60
EV=MAX
500
1000
SOURCE CURRENT,
1500
IOUTX [µA]
2000
OP amplifier Y part output voltage
(vs. sink current, VBAT = 3.0 V)
2
1.5
1.5
VYO [V]
2
1
EV=MIN
0.5
EV=MID
0
80
OP amplifier Y part output voltage
(vs. source current, VBAT = 3.0 V)
1
EV=MIN
EV=MID
0.5
EV=MID
EV=MAX
EV=MAX
0
0
0
500
1000
SOURCE CURRENT,
1500
IOUTY [µA]
2000
0
Regulator T part output voltage (VBAT = 3.0 V)
VREGTO [V]
40
EV Point
4
3.5
4.5
1.93
1.92
1.91
1.9
1.89
1.88
1.87
1.86
1.85
1.84
1.83
0
42
20
OP amplifier X part output voltage
(vs. source current, VBAT = 3.0 V)
5
VOUT3 [V]
VBAT=3V
-7
-5
0
VYO [V]
-8
500
1000
IOUT [µA]
1500
2000
Seiko Instruments Inc.
−500
−1000
−1500
SINK CURRENT, IOUTX [µA]
−2000
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
DC/DC P part output ripple voltage
(VBAT = 3.0 V, reference value)
80
90
80
70
60
50
40
30
20
10
0
Ripple [mV]
EFFIP[%]
DC/DC P part output efficiency (VBAT = 3.0 V)
EV=MIN
EV=MID
EV=MAX
0
500
1000
IOUT [µA]
1500
30
20
EV=MIN
10
0
EV=MAX
EV=MID
0
500
1000
IOUT [µA]
1500
2000
DC/DC Q part output ripple voltage
(VBAT = 3.0 V, reference value)
140
80
70
60
50
40
30
20
10
0
120
Ripple [mV]
EFFIQ[%]
50
40
2000
DC/DC Q part output efficiency (VBAT = 3.0 V)
EV=MIN
100
80
60
EV=MID
40
EV=MAX
20
EV=MIN
EV=MID
EV=MAX
0
0
500
1000
IOUT [µA]
1500
2000
DC/DC U part output efficiency (VBAT = 3.0 V)
0
500
1000
IOUT [µA]
1500
2000
DC/DC U part output ripple voltage
(VBAT = 3.0 V, reference value)
100
35
30
Ripple [mV]
80
EFFIU [%]
70
60
60
EV=MIN
40
EV=MID
20
EV=MAX
0
EV=MIN
EV=MID
EV=MAX
25
20
15
10
5
0
0
500
1000
IOUT [µA]
1500
2000
0
Seiko Instruments Inc.
500
1000
IOUT [µA]
1500
2000
43
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
Rev.6.0_01
S-8335 Series
S-8335A120FT (1/120 duty. Unless otherwise specified, these graphs show typical data for TOPR =
25°C.)
5.
DC/DC Q part output voltage
13
-10
12
-9
11
-8
VOUT2 [V]
VOUT1 [V]
DC/DC P part output voltage
10
9
VBAT=3V
8
-7
-6
-5
7
VBAT=3V
-4
6
0
20
40
60
80
0
20
DC/DC U part output voltage (VREFU = 2.92 V)
VBAT=3V
VXO [V]
VOUT3 [V]
4.5
VBAT=5V
3.5
3
20
40
60
4
3.5
3
2.5
2
1.5
1
0.5
0
80
EV=MIN
EV=MID
EV=MAX
0
EV Point
2
1.5
1.5
VYO [V]
VYO [V]
2
1
EV=MIN
EV=MID
EV=MAX
500
1000
SOURCE CURRENT,
1000
IOUTX [µA]
EV=MID
EV=MAX
1500
2000
0
IOUTY [µA]
1500
−500
−1000
SINK CURRENT,
1.73
1.72
1.71
1.7
1.69
1.68
1.67
1.66
1.65
1.64
500
2000
EV=MIN
0.5
Regulator T part output voltage (VBAT = 3.0 V)
0
1500
1
0
0
VREGTO [V]
1000
OP amplifier Y part output voltage
(vs. sink current, VBAT = 3.0 V)
0
2000
IOUT [µA]
44
500
SOURCE CURRENT,
OP amplifier Y part output voltage
(vs. source current, VBAT = 3.0 V)
0.5
80
OP amplifier X part output voltage
(vs. source current, VBAT = 3.0 V)
5
0
60
EV Point
EV Point
4
40
Seiko Instruments Inc.
−1500
IOUTY [µA]
−2000
Rev.6.0_01
STEP-UP, FOR LCD BIAS SUPPLY, 3-CHANNEL SWITCHING REGULATOR
S-8335 Series
90
80
70
60
50
40
30
20
10
0
DC/DC P part output ripple voltage
(VBAT = 3.0 V, reference value)
Ripple [mV]
EFFIP[%]
DC/DC P part output efficiency (VBAT = 3.0 V)
EV=MIN
EV=MID
EV=MAX
0
500
1000
1500
90
80
70
60
50
40
30
20
10
0
2000
EV=MIN
EV=MID
EV=MAX
0
500
IOUT [µA]
1500
2000
DC/DC Q part output ripple voltage
(VBAT = 3.0 V, reference value)
140
80
70
60
50
40
30
20
10
0
120
Ripple [mV]
EFFIQ [%]
DC/DC Q part output efficiency (VBAT = 3.0 V)
EV=MIN
EV=MID
100
80
60
EV=MIN
40
EV=MID
20
EV=MAX
EV=MAX
0
0
500
1000
1500
0
2000
500
1000
1500
2000
IOUT [µA]
IOUT [µA]
DC/DC U part output efficiency (VBAT = 3.0 V)
DC/DC U part output ripple voltage
(VBAT = 3.0 V, reference value)
100
35
80
30
Ripple [mV]
EFFIU[%]
1000
IOUT [µA]
60
EV=MID
20
EV=MAX
15
40
EV=MIN
20
EV=MID
10
EV=MAX
5
0
EV=MIN
25
0
0
500
1000
1500
2000
0
IOUT [µA]
500
1000
1500
2000
IOUT [µA]
Seiko Instruments Inc.
45
7.9±0.2
24
13
1
12
0.65
0.17±0.05
0.22±0.1
No. FT024-A-P-SD-1.0
TITLE
TSSOP24-A-PKG Dimensions
No.
FT024-A-P-SD-1.0
SCALE
UNIT
mm
Seiko Instruments Inc.
+0.1
ø1.5 -0
4.0±0.1
2.0±0.1
12.0±0.1
0.3±0.05
ø1.6±0.1
1.5±0.1
4.2±0.2
+0.4
6.5 -0.2
1
24
12
13
Feed direction
No. FT024-A-C-SD-1.0
TITLE
TSSOP24-A-Carrier Tape
FT024-A-C-SD-1.0
No.
SCALE
UNIT
mm
Seiko Instruments Inc.
21.4±1.0
17.4±1.0
+2.0
17.4 -1.5
Enlarged drawing in the central part
ø21±0.8
2.0±0.5
ø13.0±0.2
No. FT024-A-R-SD-1.0
TITLE
TSSOP24-A-Reel
FT024-A-R-SD-1.0
No.
SCALE
UNIT
QTY.
2,000
mm
Seiko Instruments Inc.
•
•
•
•
•
•
The information described herein is subject to change without notice.
Seiko Instruments Inc. is not responsible for any problems caused by circuits or diagrams described herein
whose related industrial properties, patents, or other rights belong to third parties. The application circuit
examples explain typical applications of the products, and do not guarantee the success of any specific
mass-production design.
When the products described herein are regulated products subject to the Wassenaar Arrangement or other
agreements, they may not be exported without authorization from the appropriate governmental authority.
Use of the information described herein for other purposes and/or reproduction or copying without the
express permission of Seiko Instruments Inc. is strictly prohibited.
The products described herein cannot be used as part of any device or equipment affecting the human
body, such as exercise equipment, medical equipment, security systems, gas equipment, or any apparatus
installed in airplanes and other vehicles, without prior written permission of Seiko Instruments Inc.
Although Seiko Instruments Inc. exerts the greatest possible effort to ensure high quality and reliability, the
failure or malfunction of semiconductor products may occur. The user of these products should therefore
give thorough consideration to safety design, including redundancy, fire-prevention measures, and
malfunction prevention, to prevent any accidents, fires, or community damage that may ensue.
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