TSM102AIDT - STMicroelectronics

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OPERATIONAL AMPLIFIERS

■LOW SUPPLY CURRENT : 200µA/amp.

■MEDIUM SPEED : 2.1MHz

■LOW LEVEL OUT PU T VO LTAGE CLOSE TO

VCC- : 0.1V typ.

■INPUT COMMON MODE VOLTAGE RANGE

INCLUDES GROUND

COMPARATORS

■LOW SUPPLY CURRENT : 200µA/amp.

■(VCC = 5V)

■INPUT COMMON MODE VOLTAGE RANGE

INCLUDES GROUND

■LOW OUTPUT SATURATION VOLTAG E :

250mV (Io = 4mA)

REFERENCE

■ADJUSTABLE OUTPUT VOLTAGE :

■Vref to 36V

■SINK CURRE NT CAPA BILITY : 1 to 100mA

■1% and 0. 4 % VOLTAGE PRECISIO N

■LACTH-UP IMMUNITY

DESCRIPTION

The TSM102 is a monolithic IC that includes two

op-amps, two comparators and a precision volt-

age reference. This device is offering space and

cost saving in many applications like power supply

management or data acquisition systems.

ORDER CODE

D = Small Outline Package (SO) - also available in Tape & Reel (DT)

PIN CONNECTIONS (top view)

Part Number Temperature

Range Package

TSM102I -40°C, +85°C •

TSM102AI -40°C, +85°C •

SO16

(Plastic Micropackage)

Output 1

Inverting Input 1

Non-inverting Input 1

Non-inverting Input 2

Inverting Input 2

Output 2

Vref

Output 4

Inverting Input

Non-inverting Input 4

Non-inverting Input 3

Inverting Input 3

Output 3

Cathode

COMP COMP

TSM102/A

VOLTAGE AND CURRENT CONTROLLER

January 2004

TSM102/A

2/9

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

VCC+ = 5V, VCC- = 0V, Tamb = 25°C (unless otherwise specified)

OPERATIONAL AMPLIFIER

VCC+ = 5V, VCC = GND, R1 connected to Vcc/2, T amb = 25°C (unless otherwise specified)

Symbol Parameter Value Unit

VCC DC supply Voltage 36 V

Vid Differential Input Voltage 36 V

ViInput Voltage -0.3 to +36 V

Toper Operating Free-air Temperature Range -40 to +125 °C

TjMaximum Junction Temperature 150 °C

Thermal Resistante Junction to Ambient 150 °C/W

Symbol Parameter Min. Typ Max. Unit

ICC Total Supply Current

Tmin. ≤ Tamb ≤ Tmax

0.8 1.5

2mA

Symbol Parameter Min. Typ. Max. Unit

Vio Input Offset Voltage

Tmin ≤ Tamb ≤ Tmax 14.5

6.5 mV

DVio Input Offset Vo ltage Drift 10 µV/°C

Iib Input Bias Current

Tmin ≤ Tamb ≤ Tmax 20 100

200 nA

Iio Input Offset Current

Tmin ≤ Tamb ≤ Tmax 520

40 nA

Avd

Large Signal Voltage Gain

R1=10k, Vcc+ = 30V, Vo = 5V to 25V

Tmin ≤ Tamb ≤ Tmax

25 100 V/mV

SVR Supply Voltage Rejection Ratio

Vcc = 5V to 30V 80 100 dB

Vicm Input Common Mode Rejec tion Ratio

Tmin ≤ Tamb ≤ Tmax

(Vcc-) to (Vcc+) -1.8

(Vcc-) to (Vcc+) -2.2 V

CMR Common Mode Rejection Ratio

Vcc+ = 30V, Vicm = 0V to (Vcc+) -1.8 70 90 dB

Isc

Output Short Circuit Current

Vid = ±1V, Vo = 2.5V

Source

Sink 3

VOH

High Level Output Voltage RL = 10kΩ

Vcc+ = 30V

Tmin ≤ Tamb ≤ Tmax

26 28 V

VOL Low Level Output Voltage RL = 10kΩ

Tmin ≤ Tamb ≤ Tmax 100 150

210 mV

SR Slew Rate

Vcc = ±15V

Vi = ±10V, RL = 10kΩ, CL = 100pF

1.6 2 V/µs

TSM102/A

3/9

COMPARATORS

VCC+ = 5V, VCC = Ground, Tamb = 25 °C (unless otherw ise specified)

VOLTAGE REFERENCE

GBP Gain Bandwidth Product

RL = 10kΩ, CL = 100pF, f = 100kHZ 1.4 2.1 MHz

∅mPhase Margin

RL = 10kΩ, CL = 100pF 45 Degrees

THD Toatal Harmonic Distortion 0.05 %

enEquivalent Input Noise Voltage

f = 1kHz 29

Symbol Parameter Min. Typ Max. Unit

Vio Input Offset Voltage

Tmin ≤ Tamb ≤ Tmax 5

9mV

Iio Input Offset Current

Tmin ≤ Tamb ≤ Tmax 50

150 nA

Iib Input Bias Current

Tmin ≤ Tamb ≤ Tmax 250

400 nA

IOH

High Level Output Current

Vid = 1V, Vcc = Vo = 30V

Tmin ≤ Tamb ≤ Tmax

0.1 1nA

µA

VOL

Low Level Output Voltage

Vid = -1V, Isink = 4mA

Tmin ≤ Tamb ≤ Tmax 250 400

700

Avd Large Signal Voltage Gain

R1 = 15k, Vcc = 15V, Vo = 1 to 11V 200 V/mV

Isink Output Sink Current

Vid = -1V, Vo = 1.5V 616 mA

Vicm Input Common Mode Voltage Range

Tmin ≤ Tamb ≤ Tmax 0

0Vcc+-1.5

Vcc+-2 V

Vid Differential Input Voltage Vcc+V

tre Response Time 1)

R1 = 5.1k to V cc+ ,Vref = 1.4V

1. The response time specified is for 100mV input step with 5mV overdrive.

For larger overdrive signals, 300ns can be obtained.

1.3 µs

trel Large Signal Response Time

Vref = 1.4V, Vi = TTL, R1 = 5.1k to Vcc+300 ns

Symbol Parameter Value Unit

VKA Cathode to Anode Voltage Vref to 36 V

IkCathode Current 1 to 100 mA

Symbol Parameter Min. Typ. Max. Unit

------------

TSM102/A

4/9

ELECTRICAL CHARACTERISTICS

Tamb = 25°C (unless otherwise speci fied)

Symbol Parameter Min. Typ Max. Unit

Vref

Reference Input Voltage -(figure1)- Tamb = 25°C

TSM102, VKA = Vref, IK = 10mA

TSM102A, VKA = Vref, IK = 10mA 2.475

2.490 2.500

2.500 2.525

2.510

∆Vref

Reference Input Voltage Deviation Over

Temperature Range -(figure1, note1))

VKA = Vref , IK = 10mA, Tmin ≤ Tamb ≤ Tmax

1. ∆Vref is defined as the difference between the maximum and minimum values obtained over the full temperature range.

∆Vref= Vref max. - Vref min

730

Temperature Coefficient of Reference Input Voltage - note2)

VKA = Vref , IK = 10mA, Tmin ≤ Tamb ≤ Tmax

2. The temperature coefficient is defined as the slopes (positive and negative) of the voltage vs temperature limits whithin

which the reference voltage is guaranteed.

±22 ±100 ppm/°C

Ratio of Change in Reference Input Voltage to Change in Cath-

ode to Anode Voltage -(figure2)

IK = 10mA, ∆VKA = 36 to 3V -1.1 -2

mV/V

Iref

Reference Input Current -(figure2)

IK = 10mA, R1 = 10kΩ, R2 = ∞

Tamb = 25°C

Tmin ≤ Tamb ≤ Tmax

1.5 2.5

µA

∆Iref

Reference Input Current Deviation Over

Temperature Range -(figure2)

IK = 10mA, R1 = 10kΩ, R2 = ∞

Tmin ≤ Tamb ≤ Tmax 0.5 1

µA

Imin Minimum Cathode Current for Regulation -(figure1)

VKA = Vref 0.5 1 mA

Ioff Off-State Cathode Current -(figure3) 180 500 nA

Vref

∆

T∆

---------------

Vref

∆

VKA

∆

----------------

T1 T2 Temperature

ref max.

ref min.

25°C Temperature

max

2.5V

min

- n ppm / °C

+ n ppm / °C

TSM102/A

5/9

Fi gure 1 : Test Circuit for VKA = Vref

Fi gure 2 : Test Circuit for VKA > Vref

Fi gure 3 : Test Circuit for Ioff

Vref

Input

VKA

Vref

Iref

Input

VKA Vref 1R1

--------+





Iref R1–+=

VKA

Input

Ioff

= 36V

6/9

This application note explains how to use the

TSM102 in an SMPS-type battery charger which

features :

■Voltage Control

■C urrent Control

■Low Battery Detection and End Of Charge

Detection

1 - TSM102 PRESENTATION

The TSM102 integrated circuit includes two Oper-

ational Amplifiers, two Comparators and one ad-

justable precision Voltage Reference (2.5V to

36V, 0.4% or 1%).

TSM102 can sustain up to 36V power supply volt-

age.

Fi gure 1: TSM102 P inout

2 - APPLICATION CONTEXT AND PRINCIPLE

OF OPERATION

In the battery charging fi eld which requires ever in-

creasing performances in more and more reduced

space, the TSM102A provides an attractive solu-

tion in terms of PCB area saving, precision and

versatility.

Figure 2 shows the secondary side of a battery

charger (SMPS type) where TSM102A is used in

optimised conditions : the two Operational Amplifi-

ers perform current and voltage control, the two

Comparators provide “End of Charge” and “Low

Battery” signals and the Voltage Reference en-

sures precise reference for all measuremen ts.

The TSM102A is supplied by an auxiliary power

sup ply (forward configuration - D7) regulated by a

bipolar transistor and a zener diode on its base

(Q2 and DZ), and s moothe d by the capacitors C3

and C4. R15 polarizes the base of the transistor

and at the same time limits the current through the

zen er diode during regulation m ode of the auxilia-

ry power supply.

The current and voltage regulations are made

thanks to the two Ope rational Ampl ifiers.

The f irst amplifier sens es the c urrent flow through

the sense res istor Rs and compares it with a part

of the reference voltage (resistor bridge R7, R8,

R9). The second amplifier compares the reference

voltage with a part of the charger’s output (resistor

bridge R1, R2, R3).

When either of these two operational amplifiers

tends to lower its ouput, this linear information is

pro pagated towards the prim ary side via two O R-

ing diodes (D1, D2) and an optocoupler (D3). The

compen sation loops o f these regulation functions

are ensured by the capacitors C1 and C2.

Vref

Cathod

COMP COMP

TSM102

APPL ICATION NOTE

A BATTERY CHARGER USING THE TSM102

TSM102/A

7/9

Fi gure 2 : The Application Sc hem atic - Battery Charge r Secondary Side

The first comparator ensures the “Low Battery”

signal generation thanks to the comparison of a

part of the charger’s output voltage (resistor

bridge R17, R19) and the reference voltage. Prop-

er hysteres is is given thanks to R20. An improv e-

ment t o the chargers sec urity and to the b attery’s

life time optimization is achieved by lowering the

current control measurement thanks to Q1 that

shunts the resistor R9 when the battery’s voltage

is below the “Low Battery” level.

The second comparator ensures the “End of

Charge” signal generation thanks to the compari-

son of a part of the charger’s output voltage (resis-

tor bridge R1, R2, R3) and the reference voltage.

When either of t hese t wo signals is act i ve, the cor-

responding LED is polarized for convenient visual-

ization of the battery status.

3 - CALCULATION OF THE ELEMENTS

All the components values have been chosen for a

two-Lithiu m-Ion bat teries charge application :

■C urrent Control : 720mA (Low Battery current

con trol : 250mA)

■Voltage Control : 8.4V (= 2x 4.2V)

■Low Battery : 5.6V (= 2x 2.5V + 0.6V)

■End of Charge : 8.3V (= 2x 4.15V)

Current Control :

The voltage reference is polarized thanks to the

R4 res istor (2.5mA ), and t he ca thode of the ref er-

enc e gives a fixed 2.500V voltage.

I = U / R = [Vref( R8 + R9 ) / (R7 + R8 + R9) ] / Rs

= [2.5 x (390 + 820) / (10000 + 390 + 820)] / 0.375

= 720mA

I = 720mA

P = power dissipation t hrough the sense resistor =

R I2 = 0.375 x 0.7202 = 194mW

In case of “Low Battery” conditions, the current

con trol is lowered thanks to the following

equat ion :

I = U / R = [ Vref R8 / (R7 + R8) ] / Rs

= [ 2.5 x 390 / (10000 + 390 ) ] / 0.375

= 250m A

I (LoBa tt) = 250mA

Voltage Control :

Vout = Vref / [ R2 / (R1 + R2 + R3) ]

= 2.5 / [ 56 / (131.5 + 56 + 0.68 ) ]

= 8.400V

Vout = 8.400V

Low Battery signal :

If R5 = 0Ω and R6 = open :

Vout(LoBatt) = Vref / [ R19 / ( R17 + R19 ) ]

= 2.5 / [ 10 / (12.4 + 10) ]

= 5.6V

Vout(L oBat t ) = 5.6V

En d of Charge signal :

Vout(EOC ) = Vref / [ (R2 + R3 ) / (R1 + R2 + R3 ) ]

= 2.5 / [(56 + 0.68) / (131.5 + 56 + 0.68)]

= 8.300V

Vout (EOC)= 8.300V

TSM102/A

8/9

Notes:

The current control values must be chosen in ac-

cordance with the elements of the primary side.

The performances of the battery charger in their

globality are highly depende nt on the adequ ation

of the primary and the secondary element s.

The addition of the diode D9 is necessary to avoid

dramatic discharge of the battery cells in case of

the charger disconnection from the mains voltage,

and therefore, the voltage measurement is to be

operated on the cathode side of the diode not to

take its voltage drop into account. The total bri dge

value of R1, R2, R3 must ensure low battery dis-

charge if the charger is disconnected from main,

but remain s connected to the battery by mistake.

The chos en values im pose a 44µA discharge cur-

rent max.

R12 and R13 are the equivalent resistors seen

from the opamp and from the comparat or.

A hysteresis resistor can be connected to the “End

Of Charge” co mparator to ensure prope r hystere-

sis to this signal, but this resistor must be chosen

carefully not to degrade the output voltage preci-

sion. It might be needed to impos e unidirectionna l

hysteresis (by inserting a diode on the positive

feedb ack of the comparato r).

Figure 3 shows how to use the integrated Vo ltage

Reference to build a precise Power Supply for the

TSM102A (and other components if necessary).

Pin 8 remains the reference for all voltage mea-

surement s for the rest of the application.

Fi gure 3 : A precise power supply for the TSM102A and other components

aux

TSM102 Vref

Vcc

Vaux

TSM102/A

9/9

PACKAGE MECHANICAL DATA

DIM. mm. inch

MIN. TYP MAX. MIN. TYP. MAX.

A 1.75 0.068

a1 0.1 0.2 0.004 0.008

a2 1.65 0.064

b 0.35 0.46 0.013 0.018

b1 0.19 0.25 0.007 0.010

C 0.5 0.019

c1 45˚ (typ. )

D 9.8 10 0.385 0.393

E 5.8 6.2 0.228 0.244

e 1.27 0.050

e3 8.89 0.350

F 3.8 4.0 0.149 0.157

G 4.6 5.3 0.181 0.208

L 0.5 1.27 0.019 0.050

M 0.62 0.024

S8 ˚ (max.)

SO-16 MECHANICAL DATA

PO13H

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