SGS Thomson Microelectronics TSM101C Datasheet



VOLTAGE AND CURRENTCONTROLLER

.

1.24V SERIES VOLTAGE REFERENCE WITH
10mA OUTPUT CURRENT AND 1% PRECI­SION (TSM101A)

.

TWO OPERATIONAL AMPLIFIERS WITH
ORED OUTPUT AND 1MHZ GAIN BAND­WIDTH PRODUCT

.

BUILT-IN CURRENT GENERATOR WITH EN­ABLE/DISABLEFUNCTION

.

4.5 TO 32V SUPPLYVOLTAGERANGE

.

SO8, DIP8 AND TSSOP8PACKAGES

TSM101/A

N

DIP8

(Plastic Package)

(Thin ShrinkSmall Outline Package)

(Plastic Micropackage)

P

TSSOP8

D

SO8

DESCRIPTION

The TSM101/TSM101Aintegratedcircuit incorpo­rates a highstabilityseries bandgapvoltagerefer­ence, two ORed operational amplifiers and a
current source.

This IC compares the DC voltage and the current
level at the output of a switching power supply to
an internal reference. It provides a feedback
throughan optocouplerto the PWMcontroller IC in
the primaryside.

The controlled current generator can be used to
modify the level of current limitation by offsetting
the information coming from the current sensing
resistor.

APPLICATIONS

This circuitisdesignedtobe used in battery charg­ers with a constant voltage and a limited output
current.

Itcanbeusedineverytypesofapplicationrequiring
a precision voltage regulation and current limita­tion.

Other applications include voltage supervisors,
over voltageprotection...

ORDERCODES

Part Number

TSM101C/AC -20, +80
TSM101I/AI -40,+105

PIN CONNECTIONS

Temperature

Range

1

2

3

4

Package

o

Vref

NDP

C •••

o

C •••

8

7

6

5

June 1999

1/15

TSM101/A

ABSOLUTEMAXIMUM RATINGS

Symbol Parameter Value Unit

V

CC

I

out

P

V

I

in

T

stg

T

T

thja

Notes : 1. All voltages values, except differential voltage are with respectto network ground terminal

OPERATING CONDITIONS

Symbol Parameter

V

CC

T

oper

DC Supply Voltage - (note 1) 36 V
Output Current - (note 2) 20 mA
Power Dissipation 200 mW

d

Input Voltage - (note 3) -0.3, VCC-1.5 V

in

Input Current ±1mA
Storage Temperature -40 to +125
Maximum Junction Temperature 150

j

Thermal Resistante Junction to Ambiant 130 to 200

2. The voltagereference isnot protected against permanent short circuit

TSM101C/AC/I/AI

Value

Supply Voltage 4.5 to 32 V
Operating FreeAir TemperatureRange T

min.

to T

max.

o
o

o

C/W

Unit

o

C
C

C

ELECTRICAL CHARACTERISTICS

=25oC, VCC=15V (unless otherwisespecified)

T

amb

OPERATIONALAMPLIFIER : TSM101C/I/AC/AI

Symbol Parameter Test Conditions Min. Typ. Max. Unit

Total Supply Current VCC= 15V 2 mA

I

CC

Input Voltage Range 0 VCC-1.5V V

V

i

Input Offset Voltage 25oC

V

io

I

Input Bias Current

ib

Output Sink Current, Vol= 2.5V 25oC

I

sink

A

Large Signal Voltage Gain RL=2kΩ

vo

= 1.2V on pin 7 and Vin= 0V on pin 5 25oC

@V

in

SVR Supply VoltageRejection Ratio T

CMR Common Mode Rejection Ratio T

GBP Gain Bandwidth Product V

Output Leakage Current 25oC

I

oh

CC

V

in

T

min.<Tamb.<Tmax.

T

min.<Tamb.<Tmax.

T

min.<Tamb.<Tmax.

T

min.<Tamb.<Tmax.
min.<Tamb.<Tmax.
min.<Tamb.<Tmax.

= 15V, F = 100kHz

= 10mV, RL = 2kΩ

= 100pF

C

L

T

min.<Tamb.<Tmax.

-5

-7

-700

-1000

15

7

-300 0
0

15 mA

8

15
65 90 dB

80 dB

1 MHz

2
7

V/mV

mV

nA

µA

2/15

ELECTRICAL CHARACTERISTICS

=25oC, VCC=15V (unlessotherwisespecified)

T

amb

VOLTAGEREFERENCE : TSM101

TSM101/A

Symbol Parameter Test Conditions

Reference Voltage I

V

ref

Temperature Stability T

K

vt

R
R

Load Regulation 1 < I

eglo

Line Regulation 5 < Vin< 32V 3.5 10 3.5 10 mV

egli

= 1mA, T

out

min.<Tamb.<Tmax.

out

=25oC 1.21 1.24 1.27 1.21 1.24 1.27 V

amb.

< 10mA 5 15 5 15 mV

VOLTAGE REFERENCE : TSM101A

Symbol

V

ref

K

vt

R

eglo

R

egli

Parameter

Reference Voltage I
Temperature Stability T
Load Regulation 1 < I

Test Conditions

= 1mA, T

out

min.<Tamb.<Tmax.

amb.

< 10mA 5 15 5 15 mV

out

=25oC 1.227 1.24 1.252 1.227 1.24 1.252 V

Line Regulation 5 < Vin< 32V 3.5 10 3.5 10 mV

CURRENT GENERATOR : TSM101,TSM101A

Symbol Parameter Test Conditions

Current Source 1.4 1.4 mA

I

o

Temperature Stability T

K

cgt

Line Regulation 4.5 < VCC< 32V 0.003 0.03 0.003 0.03 mA

C

glir

V

V

I

I

csleak

Voltage at the enable

csen

pin to have

= 1.4mA

I

O

Voltage at the enable

csdis

pin to have

= 0mA

I

O

Input Current on the

csen

pin

C

sen

Leakage Current Vcs=2V

min.<Tamb.<Tmax.

T

min.<Tamb.<Tmax.

T

min.<Tamb.<Tmax.

T

min.<Tamb.<Tmax.

T

min.<Tamb.<Tmax.

TSM101C TSM101I

Min. Typ. Max. Min. Typ. Max.

Unit

30 100 35 120 ppm/oC

TSM101AC TSM101AI

Min. Typ. Max. Min. Typ. Max.

Unit

30 100 35 120 ppm/oC

TSM101C/AC TSM101I/AI

Min. Typ. Max. Min. Typ. Max.

Unit

500 600 ppm/oC

0.6 0.6 V

22V

30 30 µA

µA

0.5 2 0.5 2

3/15

TSM101/A

8

Vref
Gnd

1

4
7

Vref

Vrin
Cse n
Crref

Crin

2

3
5

DESCRIPTION

Name Pin Type Function

V

ref

V

rin

C

rin

C

rref

C

sen

OUTPUT 6 OUTPUT Output pin common to the voltage regulation and current limitation

V

CC

GND 4 INPUT Ground

1 OUTPUT Voltage Reference Output 1.24V, 10mA max. Do notshort circuit
7 INPUT Voltage Regulation Loop Input
5 INPUT Current Limitation Loop Input, connected to the sense resistor
3 INPUT Current Limitation Reference Input
2 INPUT Current source enable input. This current source can be used to

offset the voltage measurement on the sense resistor and therefore to
modify the charge current. The current source is enabled when the
input voltage on pin 2 is lower than 0.8V.

loops. This output can drivethe primary side (LED) of an optocoupler.

8 INPUT Power Supply Input (4.5 to 32VDC)

+Vcc

6

OUTPUT

4/15

TSM101/A

APPLICATION NOTE

A BATTERY CHARGER USING THE TSM101

by S. LAFFONT and R. LIOU

This technical note showshow to use theTSM101
integrated circuit with a switching mode power
supply(SMPS) to realize a battery charger.

An exampleof realizationofa12VNickel-cadmium
battery chargeris given.

1 - TSM101PRESENTATION

The TSM101integratedcircuit incorporatesahigh
stability series band gap voltage reference, two
ORed operational amplifiers and a current source
(Figure 1)

Figure 1 : TSM101Schematic Diagram

1

Vref

2

3

4

This IC compares the DC voltage and the current
level at the output of a switching power supply to
an internal reference.It provides a feedback
throughan optocouplerto the PWMcontroller IC in
the primaryside.

The controlled current generator can be used to
modify the level of current limitation by offsetting
the information coming from the current sensing
resistor.

8

7

6

5

A great majority of low or medium end power
supplies is voltage regulated by using shunt pro­grammablevoltage referenceslike the TL431
(Figure 2).

Thegalvanic insulation of the controlinformationis
doneby using an opto-couplerin linearmode with
a variable photo current depending on the differ­ence between the actual output voltage and the
desiredone.

A current limitation is used to protect the power
supply against short circuits, but lacks precision.
This limitation is generally realized by sensing the
currentof the power transistor,in the primaryside
of the SMPS.

Therole of theTSM101isto makea fineregulation
of the output current of the SMPS and a precise
voltagelimitation.

The primary current limitation is conserved and
acts as a security for a fail-safe operation if a
short-circuit occursat the output of the charger.

2 - PRINCIPLE OF OPERATION

Thecurrent regulation loop and the voltagelimita­tion loop use an internal 1.24V band-gap voltage
reference.This voltage referencehas a good pre­cision(better than1.5%) and exhibitsa verystable
temperaturebehavior.

The current limitation is performed by sensing the
voltageacross thelowohmicvalueresistor R5and
comparing it to a fixed value set by the bridge
composedby R2and R3 (Figure 3).

Whenthe voltageon R5 is higher than the voltage
on R3 the output of the current loop operational
amplifier decreases. The optocoupler current in­creasesand tends to reducethe output voltage by
the way of the PWM controller.

Thevoltage regulationisdonebycomparinga part
of the output voltage (resistor bridge R6, R7 and
P1) to the voltagereference(1.24V).

If this part is higher than 1.24V, the output of the
voltageloop operationalamplifierdecreases.

5/15