IK3051AS2T

TECHNICAL DATA
Constant Voltage and Constant Current Controller
for Adaptors and Battery Chargers
IK3051A
Description
IK3051A is a highly integrated solution for SMPS
applications requiring constant voltage and constant
current mode.
IK3051A integrates one voltage reference, two
operational amplifiers (with ORed outputs – common
collectors), and a current sensing circuit.
The voltage reference combined with one operational
amplifier makes it an ideal voltage controller, and the
other low voltage reference combined with the other
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 bridge to be connected to the output of
the power supply (adapter, battery charger) to set
the voltage regulation by dividing the 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 voltage threshold.
 Optional compensation components (R and C).
IK3051A, is ideal for smallest package available, is
ideal for space shrinked applications such as adapters
and battery chargers.
Features
 CONSTANT VOLTAGE AND CONSTANT CURRENT
CONTROL
 LOW VOLTAGE OPERATION
 PRECISION INTERNAL COMPONENT COUNT
 CURRENT SINK OUTPUT STAGE
 EASY COMPENSATION
 LOW AC MAINS VOLTAGE REJECTION
Pin Definitions and Functions
SOT23-6 Pinout
Name
Pin#
Type
Vcc
6
Power Supply
GND
2
Power Supply
Vctrl
1
Analog Input
Ictrl
4
Analog Input
Out
3
Current Sink Output
Vsense
5
Analog Input
Function
Positive Power Supply Line
Ground Line. 0V Reference For All Voltages
Input Pin of the Voltage Control Loop
Input Pin of the Current Control Loop
Output Pin. Sinking Current Only
Input Pin of the Current Control Loop
2011, February, Rev. 01
IK3051A
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
o
C
o
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 under “recommended operating conditions” is not implied.
Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
Operation Conditions
Symbol
Vcc
Parameter
DC Supply Conditions
Value
2.5 to 12
Unit
V
Electrical Characteristics
Tamb = 25C and Vcc = +5V (unless otherwise specified)
Symbol
Parameter
Total Current Consumption
Total Supply Current – not taking the
Icc
output sinking current into account
Voltage Control Loop
Transconduction Gain (Vctrl). Sink
Gmv
1)
Current Only
Vref
Voltage Control Loop Reference
Iibv
Input Bias Current (Vctrl)
2)
Current Control Loop
Transconduction Gain (Ictrl). Sink
Gmi
3)
Current Only
4)
Vsense
Current Control Loop Reference
Iibi
Current out of pin Ictrl at -200mV
Output Stage
Low output voltage at 10 mA sinking
Vol
current
Output Short Circuit Current. Output
Ios
to Vcc. Sink Current Only
Test Condition
Min
Tamb
0 < Tamb < 85°C
Tamb
0 < Tamb < 85°C
Tamb
0 < Tamb < 85°C
Tamb
0 < Tamb < 85°C
Tamb
0 < Tamb < 85°C
Iout = 2.5 mA Tamb
0 < Tamb < 85°C
Tamb
0 < Tamb < 85°C
Tamb
0 < Tamb < 85°C
Tamb
0 < Tamb < 85°C
Typ
Max
1.1
1.2
2
1
3.5
2.5
1.204
1.186
1.21
Unit
mA
mA/mV
1.216
1.234
V
50
100
nA
1.5
7
mA/mV
196
192
200
204
208
mV
25
50
μA
200
mV
27
35
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 transconductance operational amplifier. The internal Voltage Reference is fixed by bandgap, and trimmed to 0.5% accuracy
at 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 trans-conduction
operational amplifier.
2011, February, Rev. 01
IK3051A
Figure 1 : Typical Adapter or Battery Charger Application Using IK3051A
In the above application schematic, the IK3051A is used on the secondary side of a flyback adapter (or
battery charger) to provide an accurate control of voltage and current. The above feedback loop is made
with an optocoupler.
2011, February, Rev. 01
IK3051A
Figure 3: Vref vs Ambient Temperature
Figure 4: Vsense pin input bias current vs
Ambient Temperature
Figure 5: Output short circuit current vs
Ambient Temperature
Figure 6: Vsense vs Ambient Temperature
Figure 7: Ictrl pin input bias current vs
Ambient Temperature
Figure 8: Supply current vs
Ambient Temperature
2011, February, Rev. 01
IK3051A
PACKAGE DIMENSION
SOT-23-6
Symbol
A
A1
A2
b
c
D
E
E1
e
e1
L
L1
θ
Dimensions In Millimeters
Min
1.050
0.000
1.050
0.300
0.100
2.820
1.500
2.650
Max
1.250
0.100
1.150
0.500
0.200
3.020
1.700
2.950
Dimensions In Inches
Min
0.041
0.000
0.041
0.012
0.004
0.111
0.059
0.104
0.950TYP
1.800
0.037TYP
2.000
0.071
0.600REF
0.300
0°
Max
0.049
0.004
0.045
0.020
0.008
0.119
0.067
0.116
0.079
0.024REF
0.600
8°
0.012
0°
0.024
8°
2011, February, Rev. 01