HTC TJ1051CL

CONSTANT VOLTAGE AND CONSTANT CURRENT CONTROLLER
FOR ADATPTORS AND BATTERY CHARGERS
FEATURES
SOT-23-6LD
● CONSTANT VOLTAGE AND CONSTANT CURRENT
CONTROL
● LOW VOLTAGE OPERATION
● PRECISION INTERNAL COMPONENT COUNT
● CURRENT SINK OUTPUT STAGE
● EASY COMPENSATION
● LOW AC MAINS VOLTAGE REJECTION
DESCRIPTION
TJ1051 is a highly integrated solution for SMPS
applications requiring constant voltage and constant
current mode.
TJ1051 integrates one voltage reference, two operational
amplifiers (with ORed ouputs - common collectors), and
a current sensing circuit.
The voltage reference combined with one operational
amplifiers makes it an ideal voltage controller, and the
TJ1051
SOP-8
ORDERING INFORMATION
Device
Marking
Package
TJ1051CL
1051
SOT-23-6LD
TJ1051CD
TJ1051
SOP-8
PIN CONNECTIONS (TOP VIEW)
SOP-8
SOT-23-6
1
Vctrl
Vcc
6
2 Gnd Vsense
5
other low voltage reference combined with the other
Ictrl
3 Out
operational amplifier makes it an ideal current limiter
for output low side current sensing.
The current threshold is fixed and precise.
The only external components are :
● A resistor brideg to be connected to the output
Block Diagram
of the power supply (adaptor, battery charger)
to set the voltage regulation by dividing the
1.210V
desired output voltage to match the internal
voltage reference value.
● A sense resistor having a value and allowable
dissipation power which need to be chosen
according to the internal vlotage threshold.
● Optional compensation components (R and C).
200mV
4
1
Vctrl
Gnd 8
2
Vcc
Out 7
3
Vsense
Ictrl 6
4 Nc
Nc 5
Vcc
Out
Vctrl
APPLICATIONS
Gnd
Ictrl
● BATTERY CHARGERS
● ADAPTERS
Vsense
TJ1051, is ideal for smallest package available, is ideal for space shrinked applications such as
battery chargers and adaptors.
HTC
Jan. 2007-Rev 1.0
1
CONSTANT VOLTAGE AND CONSTANT CURRENT CONTROLLER
FOR ADATPTORS AND BATTERY CHARGERS
TJ1051
PIN DESCRIPTION
SOT23-6 Pinout
Name
Vcc
GND
Vctrl
Ictrl
Out
Vsense
Pin#
6
2
1
4
3
5
Type
Power Supply
Power Supply
Analog Input
Analog Input
Current Shink Output
Analog Input
Function
Positive Power Supply Line
Ground Line. 0V Reference For All Voltages
Input Pin of the Voltge Control Loop
Input Pin of the Current Control Loop
Output Pin. Sinking Current Only
Input Pin of the Current Control Loop
Pin#
2
8
1
6
7
3
5
4
Type
Power Supply
Power Supply
Analog Input
Analog Input
Current Shink Output
Analog Input
Function
Positive Power Supply Line
Ground Line. 0V Reference For All Voltages
Input Pin of the Voltge Control Loop
Input Pin of the Current Control Loop
Output Pin. Sinking Current Only
Input Pin of the Current Control Loop
SOP-8 Pinout
Name
Vcc
GND
Vctrl
Ictrl
Out
Vsense
Nc
Nc
ABSOLUTE MAXIMUM RATINGS
Symbol
Vcc
Vi
Top
Tj
Parameter
DC Supply Voltage
Input Voltage
Operating Free Air Temperature Range
Maximum Junction Temperature
Value
14
-0.3 to Vcc
0 to 85
150
Unit
V
V
℃
℃
Value
2.5 to 12
Unit
V
OPERATION CONDITIONS
Symbol
Parameter
Vcc
DC Supply Conditions
HTC
Jan. 2007-Rev 1.0
2
CONSTANT VOLTAGE AND CONSTANT CURRENT CONTROLLER
FOR ADATPTORS AND BATTERY CHARGERS
TJ1051
ELECTRICAL CHARACTERISTICS
Tamb = 25℃ and Vcc = +5V (unless otherwise specified)
Symbol
Parameter
Test Condition
Min
Typ
Max
Unit
2
mA
Total Current Consumption
Icc
Total Supply Current - not taking the
Tamb
1.1
output sinking current into account
0 < Tamb < 85 ℃
1.2
Voltage Control Loop
Gmv
Transconduction Gain (Vctrl). Sink
Current Only 1)
Vref
Voltage Control Loop Referenc
Iibv
Tamb
0 < Tamb < 85 ℃
2)
Input Bias Current (Vctrl)
1
Tamb
1.198
0 < Tamb < 85 ℃
1.186
3.5
mA/mV
2.5
1.21
Tamb
50
0 < Tamb < 85 ℃
100
1.222
V
1.234
nA
Current Control Loop
Gmi
Transconduction Gain (Ictrl). Sink
Current Only 3)
Tamb
0 < Tamb < 85 ℃
4)
Vsense Current Control Loop Reference
Iibi
Current out of pin Ictrl at - 200mV
1.5
Iout =2.5mA Tamb
196
0 < Tamb < 85 ℃
192
7
200
Tamb
25
0 < Tamb < 85 ℃
50
mA/mV
204
mV
208
㎂
Output Stage
Vol
Ios
Low output voltage at 10 mA sinking
Current
Output Short Circuit Current. Output to
Vcc. Sink Current Only
Tamb
0 < Tamb < 85 ℃
200
Tamb
27
0 < Tamb < 85 ℃
35
mV
50
mA
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 (bandgap 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 bandgap, and trimmed to 0.5% accuracy
room temperature.
3) When the positive input at Ictrl is lower than - 200mV, 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 - 200mV. 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 transconduction operational amplifier.
HTC
Jan. 2007-Rev 1.0
3
CONSTANT VOLTAGE AND CONSTANT CURRENT CONTROLLER
FOR ADATPTORS AND BATTERY CHARGERS
TJ1051
Figure 1 : Typical Adaptor or Battery Charger Application Using TJ1051
D
OUT
Top primary
TJ1051
R2
Vcc
Rout Rvc Cvc1
2.2n
1
Out
Vctrl
Cic1
2.2nF
200mV
Gnd
Ictrl
IL
Cvc2
22pF
Load
1.210V
Vsense
+
Ric1
22K
R1
+
Ric2
500
Vsense
Rsense
OUT
IL
In the avove application schematic, the TJ1051 is used on the secondary side of a flyback adapte
(or battary charger) to provide an accurate control of voltage and current. The above feedback loo
is made with an optocoupler.
HTC
Jan. 2007-Rev 1.0
4