KODENSHI SN71052

SN71052
Constant voltage and constant current controller
for battery chargers and adapters
Semiconductor
Description
http:// www.auk.co.kr
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.
The external components needed to complete the two control loops are:
■ A resistor divider that senses the output of the power supply
SOT-26
(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
Application
◈ Battery chargers
Product
Marking
Package
SN71052
702
SOT-26
◈ AC to DC adapters
Block Diagram
▲ Marking Detail Information
702(①)□(②)
① Device Code
② Week Code
KSD-I5P012-000
Dec, 2011 REV. 00
1
SN71052
◈ Pin connection
1 : Vctrl
2 : GND
3 : OUT
4 : Ictrl
5 : Vsense
6: Vcc
6
5
4
1
2
3
◈ 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.
2
GND
Ground. Return of the bias current of the device. 0 V reference for all
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.
3
OUT
Common open-drain output of the two internal Op-Amps. The pin, able to
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
6
Vcc
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,
located as close to IC’s pins as possible, might be useful to get a clean
supply voltage.
KSD-I5P012-000
Dec, 2011 REV. 00
2
SN71052
◈ Absolute Maximum Ratings ( Ta = 25℃ )
Parameter
Symbol
Limits
Unit
DC Supply Voltage
VCC
-0.3 to 23
V
Power Dissipation
Pd
500
mW
Maximum Junction Temperature
TJmax
150
℃
Operating Junction Temperature Range
Topr
-10 ~ +85
℃
Thermal Resistance
Rthja
250
℃/ W
Storage Temperature Range
Tstg
-55 ~ +150
℃
Parameter
Symbol
Limits
Unit
DC Supply Voltage
VCC
2.5 to 20
V
◈ Operating Condition ( Ta = 25℃ )
KSD-I5P012-000
Dec, 2011 REV. 00
3
SN71052
◈ Electrical characteristics
( VCC=+5V, TA=25℃ ; unless otherwise specified )
Characteristic
Symbol
Test Condition
Min.
Typ.
Max.
Ta = 25℃
-
0.8
2
0 < Ta < 85℃
-
1.5
-
Ta = 25℃
1
3.0
-
0 < Ta < 85℃
-
2.5
-
Ta = 25℃
1.198
1.210
1.222
0 < Ta < 85℃
1.186
1.210
1.234
Ta = 25℃
-
40
-
0 < Ta < 85℃
-
100
-
1.5
7.0
-
-
-
-
Iout = 2.5 ㎃, Ta = 25℃
97
100
103
0 < Ta < 85℃
96
-
104
Ta = 25℃
-
25
-
0 < Ta < 85℃
-
30
-
Unit
[Total Current Consumption]
Quiescent Current
ICC
㎃
[ Voltage Control Loop OP-AMP ]
Transconductance Gain
Sink Current Only (1)
Gmv
Voltage Control Loop Reference (2)
Vref
Inverting Input Bias Current
libv
㎃/㎷
V
㎁
[Current Control Loop]
Transconductance Gain
sink Current Only (3)
Current Loop Reference (4)
Current out of pin ICTRL at -100mV
Gmi
Vsense
Iibi
Ta = 25℃
0 < Ta < 85℃
㎃/㎷
㎷
㎂
[Output Stage]
Low output Voltage at 10mA
Sink current
Vol
-
-
200
-
㎷
Output Short Circuit Current.
Output to VCC. Sink Current Only
Ios
-
-
35
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.
KSD-I5P012-000
Dec, 2011 REV. 00
4
SN71052
◈ SOT-26 Outline Dimension
(Unit : mm)
※ Recommend PCB solder land
KSD-I5P012-000
Dec, 2011 REV. 00
[Unit: mm]
5
SN71052
The AUK Corp. products are intended for the use as components in general electronic
equipment (Office and communication equipment, measuring equipment, home
appliance, etc.).
Please make sure that you consult with us before you use these AUK Corp. products
in equipments which require high quality and / or reliability, and in equipments which
could have major impact to the welfare of human life(atomic energy control, airplane,
spaceship, transportation, combustion control, all types of safety device, etc.). AUK
Corp. cannot accept liability to any damage which may occur in case these AUK Corp.
products were used in the mentioned equipments without prior consultation with AUK
Corp..
Specifications mentioned in this publication are subject to change without notice.
KSD-I5P012-000
Dec, 2011 REV. 00
6