End of Life. Last Available Purchase Date is 31-Dec-2014
Si9120
Vishay Siliconix
Universal Input Switchmode Controller
FEATURES
10- to 450-V Input Range
Current-Mode Control
125-mA Output Drive
Internal Start-Up Circuit
Internal Oscillator (1 MHz)
SHUTDOWN and RESET
DESCRIPTION
to supply 30 W of output power at 100 kHz. These devices,
when combined with an output MOSFET and transformer, can
be used to implement single-ended power converter
topologies (i.e., flyback and forward).
The Si9120 is a BiC/DMOS integrated circuit designed for use
in low-power, high-efficiency off-line power supplies.
High-voltage DMOS inputs allow the controller to work over a
wide range of input voltages (10- to 450-VDC). Current-mode
PWM control circuitry is implemented in CMOS to reduce
quiescent current to less than 1.5 mA.
The Si9120 is available in both standard and lead (Pb)-free
16-pin plastic DIP and SOIC packages which are specified to
operate over the industrial temperature range of −40 C to
85 C.
A CMOS output driver provides high-speed switching for
MOSFET devices with gate charge, Qg, up to 25 nC, enough
FUNCTIONAL BLOCK DIAGRAM
FB
COMP
15
DISCHARGE
14
10
OSC
IN
9
Error
Amplifier
VREF
−
+
11
OSC
OUT
8
OSC
2V
−
4 V (1%)
Current-Mode
Comparator
+
Ref
Gen
To
VCC
Clock (1/2 fOSC)
R
Q
5
S
6
+
−
C/L
Comparator
OUTPUT
−VIN
1.2 V
BIAS
VCC
+VIN
16
Current
Sources
7
To
Internal
Circuits
1
4
VCC
−
8.1 V
+
Undervoltage Comparator
S
Q
R
12
13
SENSE
SHUTDOWN
RESET
−
+
8.6 V
Pre-Regulator/Start-Up
Applications information, see AN707 and AN708.
Document Number: 70006
S-42042—Rev. H, 15-Nov-04
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1
Si9120
Vishay Siliconix
ABSOLUTE MAXIMUM RATINGS
Voltages Referenced to −VIN (Note: VCC < +VIN + 0.3 V)
Power Dissipation (Package)b
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 V
16-Pin Plastic DIP (J Suffix)c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 mW
+VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450 V
16-Pin SOIC (Y Suffix)d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 900 mW
Logic Inputs (RESET
SHUTDOWN, OSC IN, OSC OUT) . . . . . . . . . . . . . . . −0.3 V to VCC + 0.3 V
Thermal Impedance (QJA)
Linear Input
(FEEDBACK, SENSE, BIAS, VREF) . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 7 V
16-Pin SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140_C/W
HV Pre-Regulator Input Current (continuous) . . . . . . . . . . . . . . . . . . . . 5 mAa
Continuous Output Current (Source or Sink) . . . . . . . . . . . . . . . . . . . 125 mA
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65 to 150_C
Operating Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40 to 85_C
Junction Temperature (TJ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150_C
16-Pin Plastic DIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167_C/W
Notes
a. Continuous current may be limited by the applications maximum input
voltage and the package power dissipation.
b. Device mounted with all leads soldered or welded to PC board.
c. Derate 6 mW/_C above 25_C.
d. Derate 7.2 mW/_C above 25_C.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation
of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
RECOMMENDED OPERATING RANGE
Voltages Referenced to −VIN
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.5 V to 13.5 V
ROSC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 kW to 1 MW
+VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 V to 450 V
Linear Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to VCC − 3 V
fOSC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 kHz to 1 MHz
Digital Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to VCC
SPECIFICATIONSa
Specific Test Conditions
Parameter
Symbol
LIMITS
D Suffix −40 to 85_C
DISCHARGE = −VIN = 0 V,
VCC = 10 V +VIN = 300 V
RBIAS = 390 kW, ROSC = 330 kW
TEMPB
MINC
TYPD
MAXC
Unit
OSC IN = − VIN (OSC Disabled)
RL = 10 MW
Room
Full
3.88
3.82
4.0
4.12
4.14
V
Room
15
30
45
kW
Room
70
100
130
mA
0.5
1.0
mV/_C
Reference
Output Voltage
VR
Output Impedancee
ZOUT
Short Circuit Current
ISREF
Temperature Stabilitye
TREF
VREF = −VIN
Full
Oscillator
Maximum Frequencye
Initial Accuracy
Voltage Stability
Temperature Coefficiente
fMAX
fOSC
Df/f
ROSC = 0
Room
1
3
CSTRAY Pin 9 5 pF
ROSC = 330 kW
Room
80
100
120
CSTRAY Pin 9 5 pF
ROSC = 150 kW
Room
160
200
240
Df/f = f(13.5 V) − f(9.5 V) / f(9.5 V)
Room
10
15
%
Full
200
500
ppm/_C
4.08
V
TOSC
MHz
kHz
Error Amplifier
VFB
FB Tied to COMP
OSC IN = − VIN (OSC Disabled)
Room
Input BIAS Current
IFB
OSC IN = − VIN, VFB = 4 V
Room
25
500
nA
Input OFFSET Voltage
VOS
OSC IN = − VIN
Room
15
40
mV
Open Loop Voltage Gaine
AVOL
OSC IN = − VIN
Room
60
80
dB
BW
OSC IN = − VIN
Room
1.0
1.5
MHz
Feedback Input Voltage
Unity Gain Bandwidthe
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3.92
Document Number: 70006
S-42042—Rev. H, 15-Nov-04
Si9120
Vishay Siliconix
SPECIFICATIONSa
Specific Test Conditions
Parameter
LIMITS
D Suffix −40 to 85_C
Symbol
DISCHARGE = −VIN = 0 V,
VCC = 10 V +VIN = 300 V
RBIAS = 390 kW, ROSC = 330 kW
TEMPB
ZOUT
Error Amp configured for 60 dB gain
Source VFB = 3.4 V
Sink VFB = 4.5 V
Room
0.12
0.15
PSRR
9.5 V VCC 13.5 V
Room
50
70
VSOURCE
VFB = 0 V
Room
1.0
1.2
1.4
V
td
VSENSE = 1.5 V, See Figure 1
Room
100
150
ns
10
mA
TYPD
MAXC
Unit
Room
1000
2000
W
Room
−2.0
−1.4
MINC
Error Amplifier (Cont’d)
Dynamic Output Impedancee
Output Current
Power Supply Rejection
IOUT
mA
dB
Current Limit
Threshold Voltage
Delay to
Outpute
Pre-Regulator/Start-Up
Input Voltage
+VIN
IIN = 10 mA
Room
Input Leakage Current
+IIN
VCC 9.4 V
Room
450
V
VCC Pre-Regulator Turn-Off Threshold
Voltage
VREG
IPRE-REGULATOR = 10 mA
Room
7.8
8.6
9.4
Undervoltage Lockout
VUVLO
Room
7.0
8.1
8.9
V
VREG −VUVLO
VDELTA
Room
0.3
0.6
0.85
1.5
mA
15
20
mA
50
100
Supply
Supply Current
Bias Current
ICC
CL = 500 pF at Pin 5
IBIAS
Room
Room
10
Logic
SHUTDOWN Delaye
tSD
CL = 500 pF, VSENSE = −VIN
See Figure 2
Room
SHUTDOWN Pulse Widthe
tSW
Room
50
RESET Pulse Widthe
tRW
Room
50
Latching Pulse Width
SHUTDOWN and RESET Lowe
tLW
Room
25
Input Low Voltage
VIL
Room
Input High Voltage
VIH
Room
Input Current Input Voltage High
IIH
VIN = 10 V
Room
Input Current Input Voltage Low
IIL
VIN = 0 V
Room
−35
Output High Voltage
VOH
IOUT = −10 mA
Room
Full
9.7
9.5
Output Low Voltage
VOL
IOUT = 10 mA
Room
Full
Output Resistance
ROUT
IOUT = 10 mA, Source or Sink
Room
Full
See Figure 3
ns
2.0
8.0
1
5
−25
V
mA
Output
Rise Timee
tr
Fall Timee
tf
CL = 500 pF
0.3
0.5
Room
Room
40
20
25
30
50
40
75
75
V
W
ns
Notes
a. Refer to PROCESS OPTION FLOWCHART for additional information.
b. Room = 25_C, Cold and Hot = as determined by the operating temperature suffix.
c. The algebraic convention whereby the most negative value is a minimum and the most positive a maximum, is used in this data sheet.
d. Typical values are for DESIGN AID ONLY, not guaranteed nor subject to production testing.
e. Guaranteed by design, not subject to production test.
a. 250 V +VIN 380 V place a 10-kW, 1/4-W resistor in series with a +VIN (Pin1).
380 V +VIN 450 V place a 15-kW, 1/4-W resistor in series with a +VIN (Pin1).
Connect a 0.01-mfd capacitor between +VIN (Pin 1) and −VIN (Pin 6).
Document Number: 70006
S-42042—Rev. H, 15-Nov-04
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Si9120
Vishay Siliconix
TIMING WAVEFORMS
1.5 V −
50%
SENSE
0
VCC
SHUTDOWN
0
tr 10 ns
tSD
VCC
90%
OUTPUT
0
−
td
VCC
OUTPUT
0
−
90%
−
FIGURE 1.
FIGURE 2.
tSW
VCC
SHUTDOWN
0
tf 10 ns
50%
50%
50%
−
tr, tf 10 ns
tLW
VCC
RESET
0
50%
50%
50%
−
tRW
FIGURE 3.
TYPICAL CHARACTERISTICS
Output Switching Frequency
vs. Oscillator Resistance
f OUT (Hz)
1M
100 k
10 k
10 k
100 k
1M
rOSC − Oscillator Resistance (W)
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Document Number: 70006
S-42042—Rev. H, 15-Nov-04
Si9120
Vishay Siliconix
PIN CONFIGURATIONS AND ORDERING INFORMATION
Dual-In-Line
SOIC
+VIN
1
16
NC*
2
15
BIAS
+VIN
16
BIAS
FB
15
FB
14
COMP
RESET
NC*
3
14
COMP
SENSE
4
13
RESET
12
SHUTDOWN
11
VREF
−VIN
10
DISCHARGE
VCC
9
OSC IN
OUTPUT
−VIN
VCC
OSC OUT
5
6
7
8
1
SENSE
4
13
OUTPUT
5
12
SHUTDOWN
6
11
VREF
7
10
DISCHARGE
9
OSC IN
OSC OUT
8
Top View
Note: Pins 2 and 3 are removed
Top View
ORDERING INFORMATION
Part Number
Temperature Range
Package
Si9120DY
Si9120DY-T1
Si9120DY-T1—E3
SOIC-16
−40 to 85_C
Si9120DJ
PDIP 16
PDIP-16
Si9120DJ—E3
DETAILED DESCRIPTION
Pre-Regulator/Start-Up Section
Due to the low quiescent current requirement of the Si9120
control circuitry, bias power can be supplied from the
unregulated input power source, from an external regulated
low-voltage supply, or from an auxiliary “bootstrap” winding on
the output inductor or transformer.
When power is first applied during start-up, +VIN (pin 1) will
draw a constant current. The magnitude of this current is
determined by a high-voltage depletion MOSFET which is
connected between +VIN and VCC (pin 7). This start-up
circuitry provides initial power to the IC by charging an external
bypass capacitance connected to the VCC pin. The constant
current is disabled when VCC exceeds 8.6 V. If VCC is not
forced to exceed the 8.6-V threshold, then VCC will be
regulated to a nominal value of 8.6 V by the pre-regulator
circuit.
As the supply voltage rises toward the normal operating
conditions, an internal undervoltage (UV) lockout circuit keeps
the output driver disabled until VCC exceeds the undervoltage
lockout threshold (typically 8.1 V). This guarantees that the
Document Number: 70006
S-42042—Rev. H, 15-Nov-04
control logic will be functioning properly and that sufficient gate
drive voltage is available before the MOSFET turns on. The
design of the IC is such that the undervoltage lockout threshold
will be at least 300 mV less than the pre-regulator turn-off
voltage. Power dissipation can be minimized by providing an
external power source to VCC such that the constant current
source is always disabled.
Note: When driving large MOSFETs at high frequency without
a bootstrap VCC supply, power dissipation in the pre-regulator
may exceed the power rating of the IC package. For operation
of +VIN > 250 V, a 10-kW, 1/4-W resistor should be placed in
series with +VIN (Pin 1). For +VIN > 380 V, a 15-kW, 1/4-W
resistor is recommended.
BIAS
To properly set the bias for the Si9120, a 390-kW resistor
should be tied from BIAS (pin 16) to −VIN (pin 6). This
determines the magnitude of bias current in all of the analog
sections and the pull-up current for the SHUTDOWN and
RESET pins. The current flowing in the bias resistor is
nominally 15 mA.
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Si9120
Vishay Siliconix
DETAILED DESCRIPTION (CONT’D)
Reference Section
SHUTDOWN and RESET
The reference section of the Si9120 consists of a temperature
compensated buried zener and trimmable divider network.
The output of the reference section is connected internally to
the non-inverting input of the error amplifier. Nominal reference
output voltage is 4 V. The trimming procedure that is used on
the Si9120 brings the output of the error amplifier (which is
configured for unity gain during trimming) to within 2% of 4 V.
This compensates for input offset voltage in the error amplifier.
SHUTDOWN (pin 12) and RESET (pin 13) are intended for
overriding the output MOSFET switch via external control
logic. The two inputs are fed through a latch preceding the
output switch. Depending on the logic state of RESET.
SHUTDOWN can be either a latched or unlatched input. The
output is off whenever SHUTDOWN is low. By simultaneously
having SHUTDOWN and RESET low, the latch is set and
SHUTDOWN has no effect until RESET goes high. See
Table TABLE 1.
The output impedance of the reference section has been
purposely made high so that a low impedance external voltage
source can be used to override the internal voltage source, if
desired, without otherwise altering the performance of the
device.
Error Amplifier
Closed-loop regulation is provided by the error amplifier, which
is intended for use with “around-the-amplifier” compensation.
A MOS differential input stage provides for high input
impedance. The noninverting input to the error amplifier
(VREF) is internally connected to the output of the reference
supply and should be bypassed with a small capacitor to
ground.
Both pins have internal current source pull-ups and should be
left disconnected when not in use. An added feature of the
current sources is the ability to connect a capacitor and an
open-collector driver to the SHUTDOWN or RESET pins to
provide variable shutdown time.
TABLE 1.
TRUTH TABLE FOR SHUTDOWN AND
RESET PINS
SHUTDOWN
RESET
H
H
H
OUTPUT
Normal Operation
Normal Operation (No Change)
L
H
Off (Not Latched)
L
L
Off (Latched)
L
Off (Latched—No Change)
Oscillator Section
The oscillator consists of a ring of CMOS inverters, capacitors,
and a capacitor discharge switch. Frequency is set by an
external resistor between the OSC IN and OSC OUT pins.
(See Typical Characteristics for details of resistor value vs.
frequency.) The DISCHARGE pin should be tied to −VIN for
normal internal oscillator operation. A frequency divider in the
logic section limits switch duty cycle to 50% by locking the
switching frequency to one half of the oscillator frequency.
Output Driver
The push-pull driver output has a typical on-resistance of 20-W
maximum switching times are specified at 75 ns for a 500-pF
load. This is sufficient to directly drive MOSFETs such as the
IRF820, BUZ78 or BUZ80. Larger devices can be driven, but
switching times will be longer, resulting in higher switching
losses.
Vishay Siliconix maintains worldwide manufacturing capability. Products may be manufactured at one of several qualified locations. Reliability data for Silicon Technology and
Package Reliability represent a composite of all qualified locations. For related documents such as package/tape drawings, part marking, and reliability data, see
http://www.vishay.com/ppg?70006.
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6
Document Number: 70006
S-42042—Rev. H, 15-Nov-04
Package Information
Vishay Siliconix
SOIC (NARROW):
16-LEAD (POWER IC ONLY)
JEDEC Part Number: MS-012
MILLIMETERS
16
15
14
13
12
11
10
Dim
A
A1
B
C
D
E
e
H
L
Ĭ
9
E
1
2
3
4
5
6
7
8
INCHES
Min
Max
Min
Max
1.35
1.75
0.053
0.069
0.10
0.20
0.004
0.008
0.38
0.51
0.015
0.020
0.18
0.23
0.007
0.009
9.80
10.00
0.385
0.393
3.80
4.00
0.149
0.157
1.27 BSC
0.050 BSC
5.80
6.20
0.228
0.244
0.50
0.93
0.020
0.037
0_
8_
0_
8_
ECN: S-40080—Rev. A, 02-Feb-04
DWG: 5912
H
D
C
All Leads
e
Document Number: 72807
28-Jan-04
B
A1
L
Ĭ
0.101 mm
0.004 IN
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1
Package Information
Vishay Siliconix
PDIP: 16-LEAD (POWER IC ONLY)
16
15
14
13
12
11
10
9
E
E1
1
2
3
4
5
6
7
8
D
S
Q1
A
A1
B1
e1
Dim
A
A1
B
B1
C
D
E
E1
e1
eA
L
Q1
S
L
15°
MAX
C
B
eA
MILLIMETERS
Min
Max
INCHES
Min
Max
3.81
5.08
0.150
0.200
0.38
1.27
0.015
0.050
0.38
0.51
0.015
0.020
0.89
1.65
0.035
0.065
0.20
0.30
0.008
0.012
18.93
21.33
0.745
0.840
7.62
8.26
0.300
0.325
5.59
7.11
0.220
0.280
2.29
2.79
0.090
0.110
7.37
7.87
0.290
0.310
2.79
3.81
0.110
0.150
1.27
2.03
0.050
0.080
0.38
1.52
.015
0.060
ECN: S-40081—Rev. A, 02-Feb-04
DWG: 5920
Document Number: 72815
28-Jan-04
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1
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Revision: 01-Jan-2022
1
Document Number: 91000