SN71052.pdf 데이터시트 (총 6 페이지) - 파일 다운로드 SN71052 데이타시트 다운로드

No Preview Available !

Semiconductor
http:// www.auk.co.kr
SN71052
Constant voltage and constant current controller
for battery chargers and adapters
Description
The SN71052 is a highly integrated solution for SMPS applications
requiring a dual control loop to perform CV (constant voltage) and CC
(constant current) regulation. The SN71052 integrates a voltage reference,
Two Op-Amps (with OR-ed open-drain outputs), and a low-side current
sensing circuit. The voltage reference, along with one Op-Amp, is the core
of the voltage control loop; the current sensing circuit and the other Op-Amp
make up the current control loop.
SOT-26
The external components needed to complete the two control loops are:
A resistor divider that senses the output of the power supply
(adapter, battery charger) and fixes the voltage regulation set point at the
specified value;
A sense resistor that feeds the current sensing circuit with a voltage
proportional to the dc output current; this resistor determines the current
regulation set point and must be adequately rated in terms of power
dissipation;
Frequency compensation components (R-C networks) for both loops.
ORDERING INFORMATION
Product
SN71052
Marking
702
Package
SOT-26
Application
Battery chargers
AC to DC adapters
Block Diagram
Marking Detail Information
702()()
Device Code
Week Code
Dec, 2011 REV. 00
KSD-I5P012-000
1
Free Datasheet http://www.datasheet4u.com/

No Preview Available !

Pin connection
6
5
4
1
2
3
SN71052
1 : Vctrl
2 : GND
3 : OUT
4 : Ictrl
5 : Vsense
6: Vcc
Product Line-up
No. Name
Function
1
Vctrl
Inverting input of the voltage loop Op-Amp. The pin will be tied to the
mid-point of a resistor divider that senses the output voltage.
Ground. Return of the bias current of the device. 0 V reference for all
2
GND
voltages. The pin should be tied as close to the ground output terminal of the
converter as possible to minimize load current effect on the voltage regulation
set point.
Common open-drain output of the two internal Op-Amps. The pin, able to
3
OUT
sink current only, will be connected to the branch of the optocoupler’s
photodiode to transmit the error signal to the primary side.
4
Ictrl
Non-inverting input of the current loop Op-Amp. It will be tied directly to the
hot (negative) end of the current sense resistor
5
Vsense
Inverting input of the current loop Op-Amp. The pin will be tied to the cold end
of the current sense resistor through a decoupling resistor.
Supply Voltage of the device. A small bypass capacitor (0.1 μF typ.) to GND,
6 Vcc located as close to IC’s pins as possible, might be useful to get a clean
supply voltage.
Dec, 2011 REV. 00
KSD-I5P012-000
2
Free Datasheet http://www.datasheet4u.com/

No Preview Available !

SN71052
Absolute Maximum Ratings ( Ta = 25)
Parameter
Symbol
DC Supply Voltage
Power Dissipation
Maximum Junction Temperature
Operating Junction Temperature Range
Thermal Resistance
Storage Temperature Range
VCC
Pd
TJmax
Topr
Rthja
Tstg
Operating Condition ( Ta = 25)
Parameter
DC Supply Voltage
Symbol
VCC
Limits
-0.3 to 23
500
150
-10 ~ +85
250
-55 ~ +150
Limits
2.5 to 20
Unit
V
mW
/ W
Unit
V
Dec, 2011 REV. 00
KSD-I5P012-000
3
Free Datasheet http://www.datasheet4u.com/

No Preview Available !

SN71052
Electrical characteristics
( VCC=+5V, TA=25; unless otherwise specified )
Characteristic
Symbol Test Condition
[Total Current Consumption]
Quiescent Current
[ Voltage Control Loop OP-AMP ]
Transconductance Gain
Sink Current Only (1)
Voltage Control Loop Reference (2)
Inverting Input Bias Current
[Current Control Loop]
Transconductance Gain
sink Current Only (3)
Current Loop Reference (4)
Current out of pin ICTRL at -100mV
[Output Stage]
Low output Voltage at 10mA
Sink current
Ta = 25
ICC 0 < Ta < 85
Ta = 25
Gmv 0 < Ta < 85
Ta = 25
Vref 0 < Ta < 85
Ta = 25
libv 0 < Ta < 85
Gmi
Vsense
Iibi
Ta = 25
0 < Ta < 85
Iout = 2.5 , Ta = 25
0 < Ta < 85
Ta = 25
0 < Ta < 85
Vol -
Output Short Circuit Current.
Output to VCC. Sink Current Only
Ios
-
Min.
-
-
1
-
1.198
1.186
-
-
1.5
-
97
96
-
-
-
-
Typ.
0.8
1.5
3.0
2.5
1.210
1.210
40
100
7.0
-
100
-
25
30
200
35
Max. Unit
2
-
-
-
1.222
1.234
-
-
/
V
-
/
-
103
104
-
-
-
70
1) If the voltage on VCTRL (the negative input of the amplifier) is higher than the positive amplifier input
(Vref = 1.210V), and it is increased by 1mV, the sinking current at the output OUT will be increased by 3.5mA.
2) The internal voltage reference is set at 1.210V (band-gap reference). The voltage control loop precision takes
into account the cumulative effects of the internal voltage reference deviation as well as the input offset voltage of the
trans-conductance operational amplifier. The internal voltage reference is fixed by band-gap, and trimmed to 0.5%
accuracy at room temperature.
3) When the positive input at ICTRL is lower than -100mV, and the voltage is decreased by 1mV, the sinking
Current at the output OUT will be increased by 7mA.
4) The internal current sense threshold is set to -100mV. The current control loop precision takes into account the cumulative
effects of the internal voltage reference deviation as well as the input offset voltage of the trans-conduction operational
amplifier.
Dec, 2011 REV. 00
KSD-I5P012-000
4
Free Datasheet http://www.datasheet4u.com/

No Preview Available !

SN71052
SOT-26 Outline Dimension (Unit : mm)
Recommend PCB solder land [Unit: mm]
Dec, 2011 REV. 00
KSD-I5P012-000
5
Free Datasheet http://www.datasheet4u.com/