HT7750SA-TR(SOT23-5) 数据手册
HT77xxSA
200mA PFM Synchronous
Step-up DC/DC Converter
Features
General Description
• Low start-up voltage: 0.7V (Typ.)
The HT77xxSA devices are a high efficiency PFM synchronous step-up DC-DC converter series which are
designed to operate with both wire wound chip power
inductors and also with multi-layered chip power
inductors. The device series have the advantages of
extremely low start-up voltage as well as high output
voltage accuracy. Being manufactured using CMOS
technology ensures ultra low supply current. Because
of their higher operating frequency, up to 500 kHz, the
devices have the benefits of requiring smaller outline
type lower value external inductors and capacitors. The
higher operating frequency also offers the advantages
of much reduced audio frequency noise. The devices
require only three external components to provide a
fixed output voltage of 2.7V, 3.0V, 3.3V, 3.7V or 5.0V.
• High efficiency: 2.7V ≤ VOUT ≤ 5.0V upper 90%
(Typ.)
• High output voltage accuracy: ±2.5%
• Output voltage: 2.7V, 3.0V, 3.3V, 3.7V, 5.0V
• Output current up to 200mA
• Ultra low supply current IDD: 5μA (Typ.)
• Low ripple and low noise
• Low shutdown current: 0.1μA (Typ.)
• TO92, SOT89, SOT23 and SOT23-5 package
Applications
• Palmtops/PDAs
The HT77xxSA devices include an internal oscillator,
PFM control circuit, driver transistor, reference voltage unit and a high speed comparator. They employ
pulse frequency modulation techniques, to obtain
minimum supply current and ripple at light output
loading. These devices are available in space saving
TO92, SOT89, SOT23 and SOT23-5 packages. For
SOT23-5 package types, they also include an internal
chip enable function to reduce power consumption
when in the shutdown mode.
• Portable communicators/Smartphones
• Cameras/Camcorders
• Battery-powered equipment
Selection Table
Part No.
Output Voltage
HT7727SA
2.7V
HT7730SA
3.0V
HT7733SA
3.3V
HT7737SA
3.7V
HT7750SA
5.0V
Package
Marking
TO92
SOT89
SOT23
SOT23-5
HT77xxSA
(for TO92)
77xxSA
(for SOT89)
xxSA
(for SOT23)
xxSA (for SOT23-5)
Note: ″xx″ stands for output voltages.
Rev. 1.50
1
June 25, 2016
HT77xxSA
Block Diagram
L X
V O U T
L X L im ite r
B u ffe r
L X
V re f
O S C
P F M
V O U T
C o n tro l
C h ip E n a b le
G N D
C E
Pin Assignment
V O U T
3
F r o n t V ie w
1
2
L X
5
G N D
4
3
T o p V ie w
T o p V ie w
G N D V O U T L X
B o tto m
1
2
3
G N D
V O U T
L X
G N D
V O U T
L X
1
2
1
2
3
G N D
L X
C E
V O U T
N C
G N D
L X
C E
V O U T
N C
V ie w
Pin Description
Pin No.
Pin Name
TO92
SOT89
SOT23
—
—
—
1
CE
2
2
3
2
VOUT
—
—
—
3
NC
1
1
1
4
GND
3
3
2
5
LX
Rev. 1.40
SOT23-5
2
Description
Chip enable pin, high active
DC/DC converter output monitoring pin
No connection
Ground pin
Switching pin
June 25, 2016
HT77xxSA
Absolute Maximum Ratings
Storage Temperature ........................... -50°C to 125°C
Maximum Input Supply Voltage........................... 6.5V
Ambient Temperature Range ................ -40°C to 85°C
Note: These are stress ratings only. Stresses exceeding the range specified under "Absolute Maximum Ratings"
may cause substantial damage to the device. Functional operation of this device at other conditions beyond
those listed in the specification is not implied and prolonged exposure to extreme conditions may affect
device reliability.
Thermal Information
Symbol
θJA
PD
Parameter
Thermal Resistance (Junction to Ambient)
(Assume no ambient airflow, no heat sink)
Power Dissipation
Package
Max.
Unit
SOT89
300
°C/W
TO92
300
°C/W
SOT23
330
°C/W
SOT23-5
320
°C/W
SOT89
0.33
W
TO92
0.33
W
SOT23
0.30
W
SOT23-5
0.31
W
Note: PD is measured at Ta=25°C
Electrical Characteristics
Symbol
Ta= 25°C; VIN= VOUT×0.6; IOUT= 10mA; unless otherwise specified
Parameter
VIN
Input Voltage
ΔVOUT
Output Voltage Tolerance
VSTART
Starting Voltage(Fig.1)
VHOLD
Voltage Hold(Fig.1)
IDD1
Test Conditions
Min.
Typ.
Max.
Unit
—
—
6.0
V
-2.5
—
+2.5
%
VIN : 0 to 2V, IOUT=1mA
—
0.7
0.9
V
VIN : 2 to 0V, IOUT=1mA
—
—
0.7
V
Supply Current (Fig.2)
Measured at VOUT pin when VOUT+0.5V
—
5.0
—
μA
IDD2
Un-load Supply Current (Fig.1)
VIN=VOUT×0.6, IOUT=0mA
Measurement at VIN
—
13
26
μA
ISHDN
Shutdown Current
CE=GND
—
0.1
—
μA
ILimit
Current Limit (Fig.1)
VOUT ≤ 5.0V
650
800
—
mA
2.7V ≤ VOUT ≤ 3.3V
500
650
—
mA
2.0
—
—
V
—
—
0.4
V
—
0.05
—
μA
—
500
—
kHz
—
80
—
%
—
90
—
%
VIH
CE High Threshold
VIL
CE Low Threshold
ILEAK
LX Leakage Current (Fig.3)
fOSC
Oscillator Frequency (Fig.3)
DOSC
Oscillator Duty Cycle (Fig.3)
η
Efficiency
—
—
Add 5.5V at VOUT pin, 4V at LX pin.
Measured at LX pin.
Measured at LX pin when VOUT×0.95
2.7V ≤ VOUT ≤ 5.0V, IOUT=10mA
Note: Absolute maximum ratings indicate limits beyond which damage to the device may occur. Operating
Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific
performance limits. The guaranteed specifications apply only for the test conditions listed.
Rev. 1.40
3
June 25, 2016
HT77xxSA
L
VIN
LX
10µH
VOUT
VOUT
HT77xxSA
CIN
10µF
COUT
10µF
GND
L: ABC SR0503 10µH
CIN=COUT: muRata 10µF
Fig.1
VS
VOUT
LX
HT77xxSA
GND
Fig.2
LX
VOUT
VS
HT77xxSA
100Ω
GND
VX
Fig.3
Rev. 1.40
4
June 25, 2016
HT77xxSA
Application Circuits
Without CE Pin
VIN
L
10μH
LX
VOUT
VOUT
HT77xxSA
CIN
10μF
COUT
10μF
GND
With CE Pin
VIN
L
10μH
CIN
10μF
VIN
VOUT
Rev. 1.40
CE
COUT
10μF
GND
VOUT
LX
CE
VOUT
HT77xxSA
L
10μH
CIN
10μF
VOUT
LX
VOUT
HT77xxSA
GND
5
COUT
10μF
June 25, 2016
HT77xxSA
Functional Description
Application Information
The HT77xxSA is a constant on time synchronous stepup converter, which uses a pulse frequency modulation
(PFM) controller scheme. The PFM control scheme is
inherently stable. The required input/output capacitor
and inductor selections will not create situations of
instability.
Inductor Selection
Selecting a suitable inductor is an important consideration as it is usually a compromise situation between
the output current requirements, the inductor saturation
limit and the acceptable output voltage ripple. Lower
values of inductor values can provide higher output
currents but will suffer from higher ripple voltages
and reduced efficiencies. Higher inductor values can
provide reduced output ripple voltages and better
efficiencies, but will be limited in their output current
capabilities. For all inductors it must be noted however
that lower core losses and lower DC resistance values
will always provide higher efficiencies.
The device includes a fully integrated synchronous
rectifier which reduces costs (includes reduce L and C
sizes, eliminates Schottky diode cost etc.) and board
area.
Low Voltage Start-up
The devices have a very low start up voltage down to
0.7V. When power is first applied, the synchronous
switch will be initially off but energy will be transferred to the load through its intrinsic body diode.
The peak inductor current can be calculated using the
following equation:
IL ( PEAK
Shutdown
During normal device operation, the CE pin should be
either high or connected to the VOUT pin or the VIN
power source. When the device is in the shutdown
mode, that is when the CE pin is pulled low, the internal circuitry will be switched off. During shutdown,
the PMOS power transistor will be switched off.
=
V OUT × IO
V × ( V OUT − VIN )
+ IN
VIN × η
2 × V OUT × L × f OSC
Where
VIN = Input Voltage
VOUT = Output Voltage
IO = Output Current
η = Efficiency
L = Inductor
Synchronous Rectification
Capacitor Selection
A dead time exists between the N channel and P channel MOSFET switching operations. In synchronous
rectification, the P channel is replaced by a Schottky
diode. Here the P channel switch must be completely
off before the N channel switch is switched on. After
each cycle, a 30ns delay time is inserted to ensure the
N channel switch is completely off before the P channel
switch is switched on to maintain a high efficiency
over a wide input voltage and output power range.
Rev. 1.40
)
As the output capacitor selected affects both efficiency and output ripple voltage, it must be chosen with
care to achieve best results from the converter. Output
voltage ripple is the product of the peak inductor current
and the output capacitor equivalent series resistance
or ESR for short. It is important that low ESR value
capacitors are used to achieve optimum performance.
One method to achieve low ESR values is to connect
two or more filter capacitors in parallel. The capacitors
values and rated voltages are only suggested values.
6
June 25, 2016
HT77xxSA
Layout Considerations
• All tracks should be as wide as possible.
• The input and output capacitors should be placed
as close as possible to the VIN, VOUT and GND
pins.
Circuit board layout is a very important consideration
for switching regulators if they are to function properly.
• A full ground plane is always helpful for better
EMI performance.
Poor circuit layout may result in related noise problems. In order to minimise EMI and switching noise,
note the following guidelines:
Rev. 1.40
Top Layer
Bottom Layer
Top Layer
Bottom Layer
Top Layer
Bottom Layer
Top Layer
Bottom Layer
7
June 25, 2016
HT77xxSA
Typical Performance Characteristics
HT7750SA
Fig 1. Output Voltage vs. Output Current
Fig 4. Ripple Voltage vs. Output Current
Fig 2. Efficiency vs. Output Current
Fig 5. Load Transient Response
(L=10mH, CIN=COUT=10mF, VIN=3.0V)
Fig 3. Start-up & Hold-on Voltage
Fig 6. Line Transient Response
(L=10mH, CIN=COUT=10mF, VIN=3.0V)
Rev. 1.40
8
June 25, 2016
HT77xxSA
HT7750SA
Fig 7. Efficiency & Temperature
Fig 10. Start-up & Hold-on Voltage
HT7733SA
Fig 11. Ripple Voltage vs. Output Current
Fig 8. Output Voltage vs. Output Current
Fig 12. Load Transient Response
Fig 9. Efficiency vs. Output Current
(L=10mH, CIN=COUT=10mF, VIN=1.98V)
Rev. 1.40
9
June 25, 2016
HT77xxSA
Fig 16. Efficiency vs. Output Current
Fig 13. Line Transient Response
(L=10mH, CIN=COUT=10mF, VIN=1.98V)
Fig 14. Efficiency & Temperature
Fig 17. Start-up & Hold-on Voltage
HT7730SA
Fig 18. Ripple Voltage vs. Output Current
Fig 15. Output Voltage vs. Output Current
Rev. 1.40
10
June 25, 2016
HT77xxSA
Fig 19. Load Transient Response
Fig 20. Line Transient Response
(L=10mH, CIN=COUT=10mF, VIN=1.8V)
Rev. 1.40
(L=10mH, CIN=COUT=10mF, VIN=1.8V)
11
June 25, 2016
HT77xxSA
Package Information
Note that the package information provided here is for consultation purposes only. As this information may be
updated at regular intervals users are reminded to consult the Holtek website for the latest version of the Package/
Carton Information.
Additional supplementary information with regard to packaging is listed below. Click on the relevant section to be
transferred to the relevant website page.
• Package Information (include Outline Dimensions, Product Tape and Reel Specifications)
• The Operation Instruction of Packing Materials
• Carton information
Rev. 1.40
12
June 25, 2016
HT77xxSA
3-pin SOT23 Outline Dimensions
Symbol
Nom.
Max.
A
—
—
0.057
A1
—
—
0.006
A2
0.035
0.045
0.051
b
0.012
—
0.020
C
0.003
—
0.009
D
—
0.114 BSC
—
E
—
0.063 BSC
—
e
—
0.037 BSC
—
e1
—
0.075 BSC
—
H
—
0.110 BSC
—
L1
—
0.024 BSC
—
θ
0°
—
8°
Symbol
Rev. 1.40
Dimensions in inch
Min.
Dimensions in mm
Min.
Nom.
Max.
A
—
—
1.45
A1
—
—
0.15
A2
0.90
1.15
1.30
b
0.30
—
0.50
C
0.08
—
0.22
D
—
2.90 BSC
—
E
—
1.60 BSC
—
e
—
0.95 BSC
—
e1
—
1.90 BSC
—
H
—
2.80 BSC
—
L1
—
0.60 BSC
—
θ
0°
—
8°
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June 25, 2016
HT77xxSA
5-pin SOT23-5 Outline Dimensions
H
Symbol
A
Min.
Nom.
Max.
—
—
0.057
A1
—
—
0.006
A2
0.035
0.045
0.051
b
0.012
—
0.020
C
0.003
—
0.009
D
—
0.114 BSC
—
E
—
0.063 BSC
—
e
—
0.037 BSC
—
e1
—
0.075 BSC
—
H
—
0.110 BSC
—
L1
—
0.024 BSC
—
θ
0°
—
8°
Symbol
Rev. 1.40
Dimensions in inch
Dimensions in mm
Min.
Nom.
Max.
A
—
—
1.45
A1
—
—
0.15
A2
0.90
1.15
1.30
b
0.30
—
0.50
C
0.08
—
0.22
D
—
2.90 BSC
—
E
—
1.60 BSC
—
e
—
0.95 BSC
—
e1
—
1.90 BSC
—
H
—
2.80 BSC
—
L1
—
0.60 BSC
—
θ
0°
—
8°
14
June 25, 2016
HT77xxSA
3-pin SOT89 Outline Dimensions
Symbol
Dimensions in inch
Min.
Nom.
Max.
A
0.173
—
0.181
B
0.053
—
0.072
C
0.090
—
0.102
D
0.035
—
0.047
E
0.155
—
0.167
F
0.014
—
0.019
G
0.017
—
0.022
H
—
0.059 BSC
—
I
0.055
—
0.063
J
0.014
—
0.017
Symbol
Rev. 1.40
Dimensions in mm
Min.
Nom.
Max.
A
4.40
—
4.60
B
1.35
—
1.83
C
2.29
—
2.60
D
0.89
—
1.20
E
3.94
—
4.25
F
0.36
—
0.48
G
0.44
—
0.56
H
—
1.50 BSC
—
I
1.40
—
1.60
J
0.35
—
0.44
15
June 25, 2016
HT77xxSA
3-pin TO92 Outline Dimensions
Symbol
Nom.
Max.
A
0.173
0.180
0.205
B
0.170
—
0.210
C
0.500
0.580
—
D
—
0.015 BSC
—
E
—
0.010 BSC
—
F
—
0.050 BSC
—
G
—
0.035 BSC
—
H
0.125
0.142
0.165
Symbol
Rev. 1.40
Dimensions in inch
Min.
Dimensions in mm
Min.
Nom.
Max.
A
4.39
4.57
5.21
B
4.32
—
5.33
C
12.70
14.73
—
D
—
0.38 BSC
—
E
—
2.54 BSC
—
F
—
1.27 BSC
—
G
—
0.89 BSC
—
H
3.18
3.61
4.19
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June 25, 2016
HT77xxSA
Copyright© 2016 by HOLTEK SEMICONDUCTOR INC.
The information appearing in this Data Sheet is believed to be accurate at the time
of publication. However, Holtek assumes no responsibility arising from the use of
the specifications described. The applications mentioned herein are used solely
for the purpose of illustration and Holtek makes no warranty or representation that
such applications will be suitable without further modification, nor recommends
the use of its products for application that may present a risk to human life due to
malfunction or otherwise. Holtek's products are not authorized for use as critical
components in life support devices or systems. Holtek reserves the right to alter
its products without prior notification. For the most up-to-date information, please
visit our web site at http://www.holtek.com.
Rev. 1.40
17
June 25, 2016