TAIWAN SEMICONDUCTOR TS1051 User Manual

TS1051

Constant Voltage and Constant Current Controller

For Battery Chargers and Adaptors

1/9 Version: B07

SOT-26

SOP-8

General Description

TS1051 is a highly integrated solution for SMPS applications requiring CV (constant voltage) and CC (constant current) mode. TS1051 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.

Ordering Information

Part No.

Package

Packing

TS1051CX6 RF

SOT-26

3Kpcs / 7” Reel

TS1051CS RL

SOP-8

2.5Kpcs / 13” Reel

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

Application

● Battery Charger

● Adapters

Block Diagram

Pin Function Description

Name

Type

Function

CTRL

Analog Input

Input Pin of the Voltage Control Loop

VND

Power Supply

Ground Line. 0V Reference For All Voltage

Out

Current Sink Output

Output Pin. Sinking Current Only

CTRL

Analog Input

Input Pin of the Current Control Loop

SENSE

Analog Input

Input Pin of the Current Control Loop

VCC

Power Supply

Position Power Supply Line

Pin Definition:

1. V

CTRL

6. VCC

2. VND 5, V

SENSE

3. Out 4. I

CTRL

Pin Definition:

1. V

CTRL

8. VND

2. VCC 7, Out

3. V

SENSE

6. I

CTRL

4. N.C 5. N.C

TS1051

Constant Voltage and Constant Current Controller

For Battery Chargers and Adaptors

2/9 Version: B07

Absolute Maximum Rating

Parameter

Symbol

Value

Unit

DC Supply Voltage

VCC

Input Voltage

VIN

-0.3 to VCC

Operating Temperature

TOP

0 to +85

Maximum Junction Temperature Range

150 oC

SOP-8

130 oC/W

Thermal Resistance Junction to Ambient

SOT-26

Rθja

250 oC/W

Operating Condition

Parameter

Symbol

Value

Unit

DC Supply Voltage

VCC

2.5 to 12

Electrical Specifications (Ta=25

C, VIN=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. 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. 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 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

ICC

1.1 2 mA

Voltage Control Loop

Trans-conduction Gain (Vctrl) sink Current Only (Note 1)

GMW

3.5

mA/mV

Voltage Control Loop Reference (Note 2)

REF

1.198

1.21

1.222

Input Bias Current (Vctrl)

IBV

Current Control Loop

Trans-conduction Gain (Ictrl) sink Current only (Note 3)

GMI

1.5 7 --

mA/mV

Current Control Loop Reference, (Note 4) I

OUT

=2.5A,

SENSE

196

200

204

Current Out of Pin Ictrl at – 200mV

IBI

µA

Output Stage

Low Output Voltage at 10mA sinking Current

VOL

200

Output Short Circuit Current. Output to V

CC.

Sink Current Only

IOS

TS1051

Constant Voltage and Constant Current Controller

For Battery Chargers and Adaptors

3/9 Version: B07

Typical Adapter or Battery Charger Application Circuit

* In the above application schematic, the TS1051 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).

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