TS1052
Constant Voltage and Constant Current Controller
For Battery Chargers and Adaptors
1/8
Version: A12
SOT
-
26
General Description
TS1052 is a highly integrated solution for SMPS applications requiring CV (constant voltage) and CC (constant
current) mode. TS1052 integrated one voltage reference, two operational amplifiers, and a current sensing circuit.
The voltage reference combined with one operational amplifier make it an ideal voltage controller, and the other
low voltage reference combined with the other operational amplifier make 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.
Features
● Constant Voltage and Constant Current Control
● Low Voltage Operation
● Precision Internal Voltage Reference
● Low External Component Count
● Current Sink Output Stage
● Easy Compensation
● Low AC Mains Voltage Rejection
Ordering Information
Part No. Package
Packing
TS1052CX6 RFG
SOT-26 3Kpcs / 7” Reel
Note: “G” denotes for Halogen free products
Block Diagram
Application
● Battery Charger
● Adapters
Pin Function Description
Name Type Function
V
CTRL
Analog Input Input Pin of the Voltage Control Loop
V
ND
Power Supply Ground Line. 0V Reference For All Voltage
Out Current Sink Output Output Pin. Sinking Current Only
I
CTRL
Analog Input Input Pin of the Current Control Loop
V
SENSE
Analog Input Input Pin of the Current Control Loop
V
CC
Power Supply Position Power Supply Line
Pin
Definition
:
1. V
CTRL
6. V
CC
2. V
ND
5, V
SENSE
3. Out 4. I
CTRL
TS1052
Constant Voltage and Constant Current Controller
For Battery Chargers and Adaptors
2/8
Version: A12
Absolute Maximum Rating
Parameter Symbol Value Unit
DC Supply Voltage V
CC
20 V
Input Voltage V
IN
-0.3 to V
CC
V
Operating Temperature T
OP
0 to +85
o
C
Maximum Junction Temperature Range T
J
150
o
C
Thermal Resistance Junction to Ambient Rθja 250
o
C/W
Operating Condition
Parameter Symbol Value Unit
DC Supply Voltage V
CC
2.5 to 18 V
Electrical Specifications
(T
A
=25
o
C, V
IN
=5V unless otherwise noted)
Note 1: If the Voltage on Vctrl (the negative input of the amplifier) is higher than the positive amplifier input (Vref-
1.21V), and it is increased by 1mV, the sinking current at the output will be increased by 3.5mA.
Note 2: The internal Voltage reference is set at 1.21V (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 at room temperature.
Note 3: When the positive input at Ictrl is lower than -200mV, and the voltage is decreased by 1mV, the sinking
current at the output will be increased by 7mA
Note 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
Parameter Symbol Min Typ Max Unit
Total Current Consumption
Total Supply Current – not taking the output sinking
current into account I
CC
-- 1.1 2 mA
Voltage Control Loop
Trans-conduction Gain (Vctrl) sink Current Only (Note 1) G
MW
1 3.5 -- mA/mV
Voltage Control Loop Reference (Note 2) V
REF
1.198 1.21 1.222 V
Input Bias Current (Vctrl) I
IBV
-- 50 -- nA
Current Control Loop
Trans-conduction Gain (Ictrl) sink Current only (Note 3) G
MI
1.5 7 -- mA/mV
Current Control Loop Reference, (Note 4) I
OUT
=2.5A, V
SENSE
196 200 204 mV
Current Out of Pin Ictrl at – 200mV I
IBI
-- 25 -- µA
Output Stage
Low Output Voltage at 10mA sinking Current V
OL
-- 200 -- mV
Output Short Circuit Current. Output to V
CC.
Sink Current
Only I
OS
-- 27 50 mA
TS1052
Constant Voltage and Constant Current Controller
For Battery Chargers and Adaptors
3/8
Version: A12
Typical Adapter or Battery Charger Application Circuit
* In the above application schematic, the TS1052 is used on the secondary side of a fly-back adapter (or battery
charger) to provide an accurate control of voltage and current. The above feedback loop is made with an
optocoupler.
Principle of Operation and Application Hints
Voltage Control
The voltage loop is controlled via a first trans-conductance operational amplifier, the resistor bridge R1, R2, and the
optocoupler which is directly connected to the output.
The relation between the values of R1 & R2 should be chosen as following:
*R1=R2 x Vref / (Vout-Vref)
Where Vout is the desired output voltage.
To Avoid the discharge of the load, the resistor bridge R1 & R2 should be highly resistive. For this type of
application, a total value of 100KΩ (or more) would be appropriate for the resistors R1 & R2. As an example, with
R2=100KΩ, Vout=4.10V, Vref=1.21V, then R1=41.9KΩ.
Note that if the low drop diode should be inserted between the load and the voltage regulation resistor bridge to
avoid current flowing from the load through the resistor bridge, this drop should be taken into account into the
above calculations by replacing Vout by (Vout + Vdrop).
TS1052
TS1052
Constant Voltage and Constant Current Controller
For Battery Chargers and Adaptors
4/8
Version: A12
Principle of Operation and Application Hints (continues)
Current Control
The current loop is controlled via the second trans-conductance operational amplifier, the sense resistor Rsense,
and the optocoupler. The control verifies as following
* Rsense x llim = Vsense
* Rsense = Vsense / llim
Ilim is the desired limited current, Vsense is the threshold voltage for the current control loop.
As an example, with llim = 1A, Vsense = -200mV, then Rsense = 200mΩ.
Note that the Rsense resistor should be chosen taking into account the maximum dissipation (Plim) through it
during full load operation.
* Plim = Vsense x llim
As an example, with llim=1A, and Vsense=200mV, Plim=200mW.
Therefore, for most adapter and battery charger applications, a quarter-watt, or half-watt resistor to make the
current sensing function is sufficient.
Vsense threshold is achieved internally by a resistor bridge tied to the Vref voltage reference. Its middle point is
tied to the positive input of the current control operational amplifier, and its foot is to be connected to lower potential
point of the senseresistor as shown on the following figure. The resistors of this bridge are matched to provide the
best precision possible. The current siking outpits of the two trans-conductance operational amplifiers are common
(to the outpit of the IC). This makes an Oring function which ensures that whenever the current or the voltage
reaches too high values, the optocoupler is activated.
The relation between the controlled current and the controlled output voltage can be described with a square
characteristic as shown in the following V/I output-power graph
Output Voltage vs. Output Current
TS1052
Constant Voltage and Constant Current Controller
For Battery Chargers and Adaptors
5/8
Version: A12
Principle of Operation and Application Hints (continues)
Compensation
The voltage control trans-conductance operational amplifier can be fully compensated. Both of its output and
negative input are directly accessible for external compensation components.
And example of a suitable compensation network is shown in typical application circuit. It consists of a capacitor
Cvc1=2.2nF and a resistor Rcv1=470KΩ in series, connected in parallel with another capacitor Cvc2=22pF.
The current control trans-conductance operational amplifier can be fully compensated. Both of its output and
negative input are directly accessible for external compensation components. An example of suitable
compensation network is shown in typical application circuit. It consists of a capacitor Cic1=2.2nF and resistor
Ric1=22KΩ in series. When the Vcc voltage reaches 18V it could be interesting to limit the current coming through
the output in the aim to reduce the dissipation of the device and increase the stability performances of the whole
application. An example of suitable Rout value could be 330Ω in series with the optocoupler in case Vcc=12V.
Start Up and Short Circuit Conditions
The TS1052 is not provided with a high enough supply voltage in under start-up or short-circuit conditions. This is
due to the fact that the chip has its power supply line in common with the power supply line of the system.
Therefore, the current limitation can only be ensured by the primary PWM module, which should be chosen
accordingly. If the Primary current limitation is considered not to be precise enough for the application, then a
sufficient supply for the TS1052 has to be ensured under any condition. It would then be necessary to add some
circuitry to supply the chip with separate power line. This can be achieved in numerous ways, including an
additional winding on the transformer. The following schematic shows how to realize a low-cost power supply for
the TS1052 (with no additional windings). Please pay attention to the fact that in the particular case presented here,
this low-cost power supply can reach voltages as high as twice the voltage of the regulated line. Since the absolute
maximum rating of the TS1052 supply voltage is 18V, this low-cost auxiliary power supply can only be used in
applications where the regulated line voltage does not exceed 9V.
TS1052
TS1052
Constant Voltage and Constant Current Controller
For Battery Chargers and Adaptors
6/8
Version: A12
Electrical Characteristics Curve
FIGURE 1 – Vref vs Ambient Temperature
FIGURE 2 – Vsense vs Ambient Temperature
FIGURE 3 –
Vsense Input Bias Current
vs. Ambient Temperature
FIGURE 4 – Ictrl Input Bias
Current
vs. Ambient Temperature
FIGURE 5 –
Output Short Circuit Current
vs. Ambient Temperature
FIGURE 6 –
Supply Current
vs. Ambient Temperature
TS1052
Constant Voltage and Constant Current Controller
For Battery Chargers and Adaptors
7/8
Version: A12
SOT-26 Mechanical Drawing
Marking Diagram
52
= Device Code
Y
= Year Code
M
= Month Code for Halogen Free Product
(O=Jan, P=Feb, Q=Mar, R=Apl, S=May, T=Jun, U=Jul, V=Aug,
W=Sep, X=Oct, Y=Nov, Z=Dec)
L
= Lot Code
SOT-26 DIMENSION
DIM
MILLIMETERS
INCHES
MIN
TYP
MAX
MIN TYP MAX
A 0.95 BSC 0.0374 BSC
A1
1.9 BSC 0.0748 BSC
B 2.60
2.80
3.00
0.1024
0.1102
0.1181
C 1.40
1.50
1.70
0.0551
0.0591
0.0669
D 2.80
2.90
3.10
0.1101
0.1142
0.1220
E 1.00
1.10
1.20
0.0394
0.0433
0.0472
F 0.00
-- 0.10
0.00 0.0039
G 0.35
0.40
0.50
0.0138
0.0157
0.0197
H 0.10
0.15
0.20
0.0039
0.0059
0.0079
I 0.30
-- 0.60
0.0118
-- 0.0236
J 5º -- 10º 5º -- 10º
TS1052
Constant Voltage and Constant Current Controller
For Battery Chargers and Adaptors
8/8
Version: A12
Notice
Specifications of the products displayed herein are subject to change without notice. TSC or anyone on its behalf,
assumes no responsibility or liability for any errors or inaccuracies.
Information contained herein is intended to provide a product description only. No license, express or implied, to
any intellectual property rights is granted by this document. Except as provided in TSC’s terms and conditions of
sale for such products, TSC assumes no liability whatsoever, and disclaims any express or implied warranty,
relating to sale and/or use of TSC products including liability or warranties relating to fitness for a particular purpose,
merchantability, or infringement of any patent, copyright, or other intellectual property right.
The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications.
Customers using or selling these products for use in such applications do so at their own risk and agree to fully
indemnify TSC for any damages resulting from such improper use or sale.
