TSM101/A
VOLTAGE AND CURRENT CONTROLLER
.
.
.
..
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/DISABLE FUNCTION
4.5 TO 32V SUPPLY VOLTAGE RANGE
SO8, DIP8 AND TSSOP8 PACKAGES
N
DIP8
(Plastic Package)
D
SO8
(Plastic Micropackage)
P
TSSOP8
(Thin Shrink Small Outline Package)
ORDER CODES
DESCRIPTION
The TSM101/TSM101Aintegrated circuit incorporates a high stability series band gap voltage reference, 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
through an optocoupler to the PWM controller IC in
the primary side.
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 circuit is designed to be used in battery chargers with a constant voltage and a limited output
current.
It can be used in every types of applicationrequiring
a precision voltage regulation and current limitation.
Other applications include voltage supervisors,
over voltage protection...
June 1999
Part Number
TSM101C/AC
TSM101I/AI
Package
Temperature
Range
N
D
P
-20, +80oC
•
•
•
•
•
•
o
-40, +105 C
PIN CONNECTIONS
1
Vref
8
2
7
3
6
4
5
1/15
TSM101/A
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
VCC
DC Supply Voltage - (note 1)
36
V
Iout
Output Current - (note 2)
20
mA
Pd
Power Dissipation
200
mW
Vin
Input Voltage - (note 3)
Iin
Input Current
Tstg
Tj
Tthja
-0.3, VCC -1.5
V
±1
mA
Storage Temperature
Maximum Junction Temperature
Thermal Resistante Junction to Ambiant
-40 to +125
o
C
150
o
C
o
130 to 200
C/W
Notes : 1. All voltages values, except differential voltage are with respect to network ground terminal
2. The voltage reference is not protected against permanent short circuit
OPERATING CONDITIONS
Symbol
TSM101C/AC/I/AI
Parameter
VCC
Supply Voltage
Toper
Operating Free Air Temperature Range
Value
4.5 to 32
Unit
V
o
Tmin. to Tmax.
C
ELECTRICAL CHARACTERISTICS
Tamb = 25oC, VCC = 15V (unless otherwise specified)
OPERATIONAL AMPLIFIER : TSM101C/I/AC/AI
Symbol
Parameter
ICC
Total Supply Current
Vi
Input Voltage Range
Vio
Input Offset Voltage
Iib
Input Bias Current
@ Vin = 1.2V on pin 7 and Vin = 0V on pin 5
Isink
Avo
Output Sink Current, Vol = 2.5V
Large Signal Voltage Gain
Test Conditions
Min.
Typ.
VCC = 15V
0
Max.
Unit
2
mA
VCC -1.5V
V
25oC
Tmin. <T amb.<Tmax.
-5
-7
1
5
7
mV
o
-700
-1000
-300
0
0
25 C
Tmin. <T amb.<Tmax.
nA
o
15
25 C
Tmin. <T amb.<Tmax.
8
RL = 2kΩ
Tmin. <T amb.<Tmax.
15
Tmin. <T amb.<Tmax.
65
mA
V/mV
SVR
Supply Voltage Rejection Ratio
CMR
Common Mode Rejection Ratio
Tmin. <T amb.<Tmax.
80
dB
GBP
Gain Bandwidth Product
VCC = 15V, F = 100kHz
Vin = 10mV, RL = 2kΩ
CL = 100pF
1
MHz
Ioh
Output Leakage Current
25 C
Tmin. <T amb.<Tmax.
2/15
o
90
dB
2
7
µA
TSM101/A
ELECTRICAL CHARACTERISTICS
Tamb = 25oC, VCC = 15V (unless otherwise specified)
VOLTAGE REFERENCE : TSM101
Symbol
Parameter
Vref
Reference Voltage
Kvt
Temperature Stability
TSM101C
Test Conditions
Iout = 1mA, Tamb. = 25oC
TSM101I
Unit
Min.
Typ.
Max.
Min.
Typ.
Max.
1.21
1.24
1.27
1.21
1.24
1.27
V
30
100
35
120
ppm/ C
Tmin. <T amb.<Tmax.
o
Reglo
Load Regulation
1 < Iout < 10mA
5
15
5
15
mV
R egli
Line Regulation
5 < Vin < 32V
3.5
10
3.5
10
mV
VOLTAGE REFERENCE : TSM101A
Symbol
Parameter
Vref
Reference Voltage
Kvt
Temperature Stability
TSM101AC
Test Conditions
o
Iout = 1mA, Tamb. = 25 C
TSM101AI
Unit
Min.
Typ.
Max.
Min.
Typ.
Max.
1.227
1.24
1.252
1.227
1.24
1.252
V
30
100
35
120
ppm/ C
Tmin. <T amb.<Tmax.
o
Reglo
Load Regulation
1 < Iout < 10mA
5
15
5
15
mV
R egli
Line Regulation
5 < Vin < 32V
3.5
10
3.5
10
mV
CURRENT GENERATOR : TSM101, TSM101A
Symbol
Parameter
Test Conditions
TSM101C/AC
Min.
TSM101I/AI
Max.
Min.
Typ.
Max.
Unit
1.4
1.4
mA
Kcgt
Temperature Stability
Tmin. <T amb.<Tmax.
500
600
ppm/ oC
C glir
Line Regulation
4.5 < VCC < 32V
0.003
Vcsen
Voltage at the enable
pin to have
IO = 1.4mA
Tmin. <T amb.<Tmax.
Vcsdis
Voltage at the enable
pin to have
IO = 0mA
Tmin. <T amb.<Tmax.
Icsen
Input Current on the
C sen pin
Tmin. <T amb.<Tmax.
Icsleak
Leakage Current
Vcs = 2V
Tmin. <T amb.<Tmax.
Io
Current Source
Typ.
0.03
0.003
0.6
2
0.03
mA
0.6
V
2
V
30
0.5
2
30
0.5
2
µA
µA
3/15
TSM101/A
8
Vre f
Gnd
1
+Vcc
Vre f
4
7
Vrin
Cs e n
Crre f
Crin
6
2
OUTP UT
3
5
DESCRIPTION
4/15
Name
Pin
Type
Vref
1
OUTPUT
Function
Voltage Reference Output 1.24V, 10mA max. Do not short circuit
Vrin
7
INPUT
Voltage Regulation Loop Input
C rin
5
INPUT
Current Limitation Loop Input, connected to the sense resistor
Crref
3
INPUT
Current Limitation Reference Input
C sen
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.
OUTPUT
6
OUTPUT
Output pin common to the voltage regulation and current limitation
loops. This output can drive the primary side (LED) of an optocoupler.
VCC
8
INPUT
Power Supply Input (4.5 to 32VDC)
GND
4
INPUT
Ground
TSM101/A
APPLICATION NOTE
A BATTERY CHARGER USING THE TSM101
by S. LAFFONT and R. LIOU
This technical note shows how to use the TSM101
integrated circuit with a switching mode power
supply (SMPS) to realize a battery charger.
An example of realization of a 12V Nickel-cadmium
battery charger is given.
1 - TSM101 PRESENTATION
The TSM101 integrated circuit incorporates a high
stability series band gap voltage reference, two
ORed operational amplifiers and a current source
(Figure 1)
Figure 1 : TSM101 Schematic Diagram
1
Vref
A great majority of low or medium end power
supplies is voltage regulated by using shunt programmable voltage references like the TL431
(Figure 2).
The galvanic insulation of the control information is
done by using an opto-coupler in linear mode with
a variable photo current depending on the difference between the actual output voltage and the
desired one.
A current limitation is used to protect the power
supply against short circuits, but lacks precision.
This limitation is generally realized by sensing the
current of the power transistor, in the primary side
of the SMPS.
The role of the TSM101 is to make a fine regulation
of the output current of the SMPS and a precise
voltage limitation.
The primary current limitation is conserved and
acts as a security for a fail-safe operation if a
short-circuit occurs at the output of the charger.
8
2
7
3
6
4
5
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
through an optocoupler to the PWM controller IC in
the primary side.
The controlled current generator can be used to
modify the level of current limitation by offsetting
the information coming from the current sensing
resistor.
2 - PRINCIPLE OF OPERATION
The current regulation loop and the voltage limitation loop use an internal 1.24V band-gap voltage
reference. This voltage reference has a good precision (better than 1.5%) and exhibits a very stable
temperature behavior.
The current limitation is performed by sensing the
voltage across the low ohmic value resistor R5 and
comparing it to a fixed value set by the bridge
composed by R2 and R3 (Figure 3).
When the voltage on R5 is higher than the voltage
on R3 the output of the current loop operational
amplifier decreases. The optocoupler current increases and tends to reduce the output voltage by
the way of the PWM controller.
The voltage regulation is done by comparing a part
of the output voltage (resistor bridge R6, R7 and
P1) to the voltage reference (1.24V).
If this part is higher than 1.24V, the output of the
voltage loop operational amplifier decreases.
5/15
TSM101/A
Figure 2 : SMPS Using a TL431 as Voltage Controller
The optocoupler current increases and tends to
reduce the output voltage by the way of the PWM
controller.
By enabling the TSM101 current source (pin 2) it is
possible to offset the current sensing by a voltage
equal to :
ence of this diode on the charge is negligible if the
voltage drop (0.7V) is taken into account during the
design of the charger.
The voltage at the output of the charger is :
R6+R7
xVr
R6
and regarding R6 and R7 :
• Vout =
• Voff # R4 * Io with Io = 1.4mA
This offset lowers the output charge current and
this function can be used to charge two types of
batteries having different capacities. The current
source is enabled by connecting pin 2 to ground
• R6 = (
3 - CALCULATION OF THE ELEMENTS
The charge current is regulated at 700mA (if the
charge control input is left open) or 200mA (if the
charge control input is put to ground ), allowing the
charge of two different types of batteries.
• R7 = 12kΩ
3.1 - Voltage limitation
The end-of- charge voltage is limited at 1.45V/cell,
this is the recommended voltage for an ambient
temperature at 25oC.
A diode is generally inserted at the output of the
charger to avoid the discharge of the battery if the
charger is not powered. This diode is sometimes
directly integrated in the battery pack. The influ6/15
Vref
) x R7
Vout − Vref
P1, which is a part of R6 and R7 is not considered
in this equation.
The following values are used on the application
board :
• R6 = 1kΩ
• P1 = 220Ω, adjust for Voutput = 15.2V with the
battery replaced by a 1kΩ resistor
• R10 = short circuit
• C3 = 100nF
3.2 - Current regulation
R5 is the sense resistor used for current measurement.
TSM101/A
The current regulation is effective when the voltage
drop across R5 is equal to the voltage on pin 5 of
the TSM101 (assuming that the internal current
source is disabled).
For medium currents (<1A), a voltage drop across
R5 of 200mV = Vr5 is a good value, R5 can be
realized with standard low cost 0.5W resistors in
parallel.
Vr5
, R5 = 0.285Ω (four 1.2Ω resistor in
Ich
parallel)
R2 and R3 can be chosen using the following
formula :
• R5 =
• R2 = R3 x
(Vref − Vr5)
Vr5
CHARGE CONTROL
If the pin 2 is left open, the charge current is nominal
at # 700mA.
If pin 2 is connected to ground, the internal current
source is enabled, the current measurement is
off-setted by a voltage equal to :
• Vr4 = Io x R4 with Io = 1.4mA
This can be used to lower the charging current or
eventually to stop the charge, if Vr4 > Vr5
In our example, the current offset is equal to 700 200mA = 500mA, representing a voltage offset
Vr4 = 140mV across R4.
The following values are used on the application
board :
• R5 = 4 *1.2Ω 0.5W in parallel
• R4 = 100Ω
• R2 = 1.2kΩ
• R3 = 220Ω
• R9 = short circuit
• R1 = 10kΩ
• C2 = 100nF
• C5 = 100nF
• C1 = output capacitor of the SMPS
• C4 = 10µF
4 - SCHEMATIC DIAGRAM
Figure 2 represents a schematic of the output
circuit of a ”classical” SMPS using a TL431 for
voltage regulation. This circuit is modified to use
the TSM101 and the final circuit is represented in
figure 3.
Figure 3 : SMPS Using the TSM101
7/15
TSM101/A
5 - IMPROVEMENT
5.2. Power supply for TSM101
5.1. High frequency compensation
In applications requiring low voltage battery charge
or when the charger is in current regulation mode,
the outputvoltage can be too low to supply correctly
the TSM101.
The same problem occurs when the output is shortcircuited.
A solution to provide a quasi constant supply voltage to the TSM101 is shown at figure 4 : an auxiliary
Two R-C devices (R9 + C2 & R10 + C3) are used
to stabilize the regulation at high frequencies.
The calculation of these values is not easy and is
a function of the transfer function of the SMPS.
A guess value for the capacitors C2 and C3 is
100nF.
Figure 4 : An Auxiliary Winding for TSM101 Power Supply
winding is added at the secondary side of the
transformer.
This winding is forward coupled to the primary
winding, the voltage across it is directly proportional
to the mains rectified voltage, even if the flyback
voltage is close to zero.
As this auxiliary winding is a voltage source, it is
necessary to add a resistor (R11) on the cathode
of the rectifier (D3) to limit the current.
8/15
A low cost regulator (Q2 and Zener diode D4) is
used to power the TSM101. This is necessary with
autoranging SMPS with wide input voltages, for
example 90 to 240V without switching. In standard
SMPS with voltage range from 200 to 240VAC or
100 to 130VAC, this regulator can be removed and
replaced by the small power supply shown on
figure 5 (Raux, Caux, D2).
TSM101/A
5.3. Higher Precision for the Voltage Control
The voltage drop through the sense resistor R5
offsets the voltage measurement. In most battery
charging applications, this offset is not taken into
account because the error is negligeable compared to the end-of-charge voltage due to the fact
that the charging current value decreases drastically during the final phase of the battery charging.
But in other applications needing highest possible
precision in voltage control, another connecting
schematic is possible for TSM101 as shown on
figure 5.
In this schematic, the 0V reference is defined as
the common point between the sense resistor, the
0V Output Voltage, the foot of the resistor bridge
R6/R7, and the ground (pin 4) of the TSM101.
TSM101A(1% internal voltage referenceprecision)
is required in such applications.
Figure 5 : Precise Output Voltage Control
5.4. An example of application where the
charging current is different according to the
charging phase.
The following application includes a specific recommendation which requires that the charging current
should be fixed to Ich1 = 800mAin normal charging
conditions, and Ich2 = 200mA when the cell voltage is below Vl=2.5V to optimize the cell life-time.
Moreover, an Charging Status LED should be
switched off when the cell voltage is above
Vh=6.5V.
Figure 6 shows how this can easily be achieved
using an additional dual comparator (type LM393)
where the first operator (C1) is used to activate the
TSM101 internal current generator to offset the
current measurement thanks to R4, and the second
(C2) is used to switch the status LED off. On figure
6, the status signal is determined by voltage measurement, this could as well be achieved by current
measurement.
If V5 = 100mV is the maximum tolerable voltage
drop through the sense resistor R5 during normal
9/15
TSM101/A
charging conditions, then the following calculations
apply :
Current Control :
R5 = V5 / Ich1 = 0.1 / 0.8 = 0.125
R5 = 125mΩ
V5 = Vref x R3 / (R2 + R3) with R2 + R3 ~ 12kΩ
and Vref = 1.24V
R3 = 1kΩ, R2 = 11.4kΩ
V5 = R4 x Io + R5 x Ich2, therefore, R4 = (V5 - R5
x Ich2) / Io with Io = 1.4mA
Figure 6 : Optimized Charging Conditions
10/15
R4 = 53.6Ω
Vref = Vl x R15 / (R14 + R15) with Vl = 2.5V and
R14 + R15 ~ 20kΩ
R15 = R14 = 10kΩ
Voltage Control :
Vref = Vh x R6 / (R6 + R7) with Vh = 6.5V and
R6 + R7 ~ 12kΩ
R6 = 2.36kΩ, R7 = 10kΩ
Vref = Vh R17 / (R16 + R17)
R17 = 10kΩ, R16 = 42kΩ
TSM101/A
EVALUATION BOARD - TECHNICAL NOTE
TSM101 integrates in the same 8 pin DIP or SO
package
• one 1.24V precision voltage reference
• two operationnal amplifiers
• two diodes which impose a NOR function on the
outputs of the operationnal amplifiers
• one current source which can be activated/ inhibited thanks to an external pin.
An immediate way to take advantage of the high
integration and reliability of TSM101 is to use it as
a voltage and current controller on power supplies
secondary. The application note AN896 describes
precisely how to use TSM101 in an SMPS battery
charger.
The TSM101 Evaluation Board is adaptable to any
power supply or battery charger (SMPS or linear)
as a voltage and current controller with minimal
constraints from the user.
HOW TO USE THE TSM101 EVALUATION
BOARD ?
The generic Electrical Schematic is shown on figure 1. It represents an incomplete SMPS power
supply where the primary side is simplified.
The ”IN+”and ”IN-” power inputs of the evaluation board should be connected directly to the
power lines of the power supply secondary.
The ”Vcc” input of the evaluation board should be
connected to the auxiliary supply line.
In the case of an SMPS power supply, the ”Reg”
output of the evaluation board should be connected to the Optocoupler input to regulate the
PWM block in the primary side. In the case of a
linear power supply, the ”Reg” output should be
connected to the base of the darlington to regulate
the power output.
A diode might be needed on the output of the
evaluation board in the case of a battery charger
application to avoid the discharge of the battery
when the charger is not connected.
COMPONENTS CALCULATIONS
The voltage control is given by the choice of the
resistor bridge R6/R7 (and the trimmer P1) due to
equation 1 :
• Vref = R6/(R6+R7)xVout
where Vref = 1.24V
eq1
Figure 1
11/15
TSM101/A
The current control is given by the choice of the
voltage drop through the sense resistor R5 (to be
linked to the nominal current of the application) and
by the value of the sense resistor itself.
For medium currents (< 1A), a good value for the
voltage drop through R5 can be Vsense = 200mV
(dissipation < 200mW).
The resistor bridge R2/R3 should be chosenfollowing equation 2 :
• Vsense = R3/(R2+R3)xVref
eq2
The total value of the resistor bridge should be in
the range of the kΩ in order to ensure a proper
charge for the voltage reference(in the range of the
mA).
To set the current limit, the sense resistor R5 should
be chosen following equation 3 :
• Ilim = Vsense/R5
eq3
The internal current generator (Isce) can be used
to offset the current limitation with a lower value.
This current generator is activated by connecting
pin 2 to ground. It is inhibited if pin 2 is connected
to the positive rail via the pull up resistor R1.
The current offset is given by the choice of the
resistor R4.
If Ilim1 is the current limit calculated in the previous
paragraph, and Ilim2 is the current limit that is to be
set when pin 2 is connected to ground, R4 should
be chosen following equation 4 :
• R4 = (Vsense - Ilim2xR5)/Isce
eq4
where Isce = 1.4mA
C4 and C5 are bypass capacitors used to
smoothen the regulated outputs.
C2 and C3 are capacitors used for high frequency
compensation.
EXAMPLES OF COMPONENT LISTS
Table 1 summerizes a few examples of component
lists to generate quickly 15V/700mA/20 0mA,
12V/1A/500mAor 8.2V/200mA/100mAvoltage and
current regulations.
12/15
Table 1
Voltage /
Current
Control
15V
700mA
200mA
12V
1A
500mA
8.2V
200mA
100mA
R1
10kΩ
10kΩ
10kΩ
R2
1.2kΩ
1.2kΩ
1.2kΩ
R3
220Ω
220Ω
220Ω
R4
100Ω
68Ω
68Ω
1Ωx1
R5
1.2Ωx4
0.8Ωx4
R6
1kΩ
1kΩ
1kΩ
R7
12kΩ
8.2kΩ
5.6kΩ
P1
100Ω
100Ω
100Ω
0Ω
0Ω
0Ω
C2
100nF
100nF
100nF
C3
100nF
100nF
100nF
C4
10µF
22µF
4.7µF
C5
100nF
100nF
100nF
2 straps
Figure 2 represents in real dimensions thePCB and
the silkscreen of the TSM101 Evaluation board.
Figure 2
TSM101/A
PACKAGE MECHANICAL DATA
8 PINS - PLASTIC DIP
Dim.
A
a1
B
b
b1
D
E
e
e3
e4
F
i
L
Z
Min.
Millimeters
Typ.
3.32
0.51
1.15
0.356
0.204
Max.
1.65
0.55
0.304
10.92
9.75
7.95
Min.
0.020
0.045
0.014
0.008
Max.
0.065
0.022
0.012
0.430
0.384
0.313
2.54
7.62
7.62
3.18
Inches
Typ.
0.131
0.100
0.300
0.300
6.6
5.08
3.81
1.52
0.125
0260
0.200
0.150
0.060
13/15
TSM101/A
PACKAGE MECHANICAL DATA
8 PINS - PLASTIC MICROPACKAGE (SO)
Dim.
A
a1
a2
a3
b
b1
C
c1
D
E
e
e3
F
L
M
S
14/15
Min.
Millimeters
Typ.
0.1
0.65
0.35
0.19
0.25
Max.
1.75
0.25
1.65
0.85
0.48
0.25
0.5
Min.
Inches
Typ.
0.026
0.014
0.007
0.010
Max.
0.069
0.010
0.065
0.033
0.019
0.010
0.020
0.189
0.228
0.197
0.244
0.004
o
45 (typ.)
4.8
5.8
5.0
6.2
1.27
3.81
3.8
0.4
0.050
0.150
4.0
1.27
0.6
0.150
0.016
o
8 (max.)
0.157
0.050
0.024
TSM101/A
PACKAGE MECHANICAL DATA
8 PINS -THIN SHRINK SMALL OUTLINE PACKAGE
Dim.
Millimeters
Min.
Typ.
A
Min.
Typ.
1.20
A1
0.05
A2
0.80
b
c
D
2.90
Max.
0.05
0.15
0.01
1.05
0.031
0.19
0.30
0.007
0.15
0.09
0.20
0.003
0.012
3.10
0.114
4.50
0.169
8o
0o
0.75
0.09
E
E1
Inches
Max.
1.00
3.00
6.40
4.30
e
4.40
0o
l
0.50
0.60
0.039
0.118
0.041
0.122
0.252
0.65
k
0.006
0.173
0.177
0.025
8o
0.0236
0.030
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15/15
APPLICATION NOTE
TSM101 USED IN A VOLTAGE SUPERVISOR
by S. LAFFONT
This technical note shows how to use the TSM101
integrated circuit to realize a voltage supervisor.
An example of realization is given.
1 - TSM101 PRESENTATION
The TSM101 integrated circuit incorporates a high
stability series band gap voltage reference, two
ORed operational amplifiers and a current source
(Figure 1).
Figure 1 : TSM101 Schematic Diagram
1
Vref
8
2
7
3
6
4
5
• the positive input (V5) of the second operator
(pin 5) is lower than 1.24V.
A resistor network (R1, R2, R3) is used to bias the
input of the two operators, when the input voltage
is out of the limits, the output (pin 6) is close to zero.
This signal can be used directly to power an optocoupler.
In our application, we have added a transistor (Q1).
This transistor is driven via a Zener diode (D1).
This circuit has two advantages :
1 - this Zener diode avoids problems encountered with many voltage supervisors : when the
supply voltage is lower than the operating voltage of those circuits, the behavior is erratic.
The minimum operating voltage of the TSM101 is
5V. With a 4.7V Zener diode, the transistor Q1 will
never be saturated if the supply voltage is lower
than 5V whatever the output of the TSM101.
2 - the optocoupler is ON only if the input voltage
is inside the specified range.
3 - CALCULATION OF THE ELEMENTS
Let assume :
• Vmin. = minimum threshold voltage
• Vmax. = maximum threshold voltage
• VCC = nominal voltage
2 - PRINCIPLE OF OPERATION AND
SCHEMATIC DIAGRAM
The two operational amplifiers are used as comparators.
The first operatorhas its + input wired to the internal
1.24V reference and the second one its - input
wired to 1.24V.
As the two operators are OR-ed internally, the
output (pin 6) is low if :
We have the following equations :
(Vmin. x (R1+R2))
= Vref
V5 =
ΣR
(Vmax. x R1)
= Vref
V7 =
ΣR
Vre x ΣRf)
R1 =
Vmax.
Vref x ΣR
R2 =
= − R1
Vmin.
• the negative input (V7) of the first operator
(pin 7) is higher than 1.24V
AN895/0299
1/2
APPLICATION NOTE
Example :
Supervision of a 12V +-5% power supply :
then :
• Vmin. = 11.4V Vmax. = 12.6V
• R2 = 200Ω
We take RΣ = 24kΩ (500µA in the resistor network)
• R3 = 21.43kΩ
• D1 = 4.7V Zener diode
• R5 = 10kΩ
• R1 = 2.36kΩ
Ib (Q1) = 500µA when ON and a current of 10mA
in the opto-coupler when ON
• R4 = 12kΩ
• R6 = 1kΩ
The complete schematic of the voltage supervisor
is represented on Figure 2.
Figure 2 : Voltage Supervisor with TSM101
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from
its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications
mentioned in this publication are subject to change without notice. This publ ication supersedes and replaces all information
previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems
without express written approval of STMicroelectronics.
The ST logo is a trademark of STMicroelectronics
1999 STMicroelectronics – Printed in Italy – All Rights Reserved
STMicroelectronics GROUP OF COMPANIES
Australia - Brazil - Canada - China - France - Germany - Italy - Japan - Korea - Malaysia - Malta - Mexico - Morocco
The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A.
http://www.st.com
2/2
APPLICATION NOTE
TSM101 IN S.M.P.S
by G. AUGUSTONI
The TSM101 is a voltage and current controller
providing a more integrated solution in Switching
Mode Power Supply application versus common
standard ICs solution, with more functions widely
used in power control in a single IC.
This application note shows three basic configurations of the IC, to be used in the secondary side of
any SMPS.
Functionsdescribed are precise secondary voltage
regulation, current limiting with foldback function,
window detector with output feedback to opto-coupler or power good signal to CPU.
1 - Voltage regulation and overcurrent control
One TSM101 is used to control each voltage output
of the SMPS controlling current and voltage.
Figure 1a shows how to use TSM101 on a single
output. Values are given for a 12V regulated output
and 10A current limit.
Voltage regulation is achieved with R2/R1 resistor
bridge comparing the voltage to TSM101 internal
1.24V voltage reference.
• Vout =1.24x(R1+R2)/R1=1.24x117/12=12.09V
The amplifier is driving on output pin 6 the optocoupler or a post regulation power MOS.
The TSM101 can also be used just as a currentand
voltage supervisor, outside the regulation loop. Replacing R2 with higher value like 110KΩ, enables
the TSM101 to detect overvoltage and overcurrent
on the 12V output. Pin 6 output is then a power
good signal. A pull up resistor on the output pin 6
may be needed.
Logic is : High - Power Ok, Low - Power failure.
Current limitation is controlled through R4/R3 resistor bridge. The threshold voltage corresponding
to the drop voltage in the shunt resistor is given by
R4 value.
In Figure 1a example, 1KΩ = 1V, so 100Ω is
100mV.
• Vth=R3/R4 x Vout
We cansee in this formula that the current limit level
is linked to the output voltage level. This is the
foldback function, when output voltage drops, current limit level drops in the same time, limiting
destruction in the load defect.
If during start up, a higher current limit is needed,
the figure 1b schematic brings a smart solution
Figure 1a : Voltage and Current Control
AN916/0299
1/3
APPLICATION NOTE
using the current source to offset the current detection level.
During start, R5-C2 time constant keeps current
source off and level for current limit is 20A(200mV).
Once C2 is charged to high level, it turns on the
current source offsetting the current limit to 10A
(100mV). Furthermore, if pin 2 (current generator
control) is connected on the power line output
(3.3V) and if a short circuit occurs, the TSM101
latches and the output remains low, needing a
system restart.
2 - Dual Overvoltage Controller
In two outputs high current power supply like 5V
and 12V for PC, the SMPS needs to protect the
load against overvoltage.The TSM101 in Figure 2a
is detecting any overvoltage on any of both output,
Figure 1b : Inrush Current and Latch on SC
Figure 2a : Overvoltage Detector
2/3
informing the system with an ored Power Good
output.
Threshold voltages are 11.1V for the 12V and 4.6V
for the 5V.
This applies to split power supply as shown in
Figure 2b.
3 - Over and Undervoltage control
The TSM101 can be used as a window comparator.
This allows to check that each output of the SMPS
is in the desired voltage range.
The application diagram is given in figure 3, where
the voltage across R2 fixes the good voltage window. In the example, the voltage across R2 gives
a 1.2V good voltage window at 12V level, from
11.5V to 12.5V. For any other output voltage,
TSM101 output will be low.
APPLICATION NOTE
Inverting input (7) and non inverting input (5) are
respectively used for overvoltage and undervoltage detection.
4 - Other informations
The TSM101 is supplied under 15V in all these
applications, referring to the specification values.
In most of applications, TSM101 can be supplied
under 4.5V.
TSM101 is available with voltage reference accuracy of 2% and 1% for the ”A” version. Compared
to market standard TL431, TSM101 has better
accuracy in line regulationand load regulation (due
to the IC structure).
Figure 2b : Split Supply Overvoltage Detector
Figure 3 : Over and Undervoltage Detector
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from
its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications
mentioned in this publication are subject to change without notice. This publ ication supersedes and replaces all information
previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems
without express written approval of STMicroelectronics.
The ST logo is a trademark of STMicroelectronics
1999 STMicroelectronics – Printed in Italy – All Rights Reserved
STMicroelectronics GROUP OF COMPANIES
Australia - Brazil - Canada - China - France - Germany - Italy - Japan - Korea - Malaysia - Malta - Mexico - Morocco
The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A.
http://www.st.com
3/3
AN896
APPLICATION NOTE
®
TSM101 USED IN A BATTERY CHARGER
by S. LAFFONT
This technical note shows how to use the TSM101
integrated circuit with a switching mode power
supply (SMPS) to realize a battery charger.
An example of realization of a 12V Nickel-cadmium
battery charger is given.
1 - TSM101 PRESENTATION
The TSM101 integrated circuit incorporates a high
stability series band gap voltage reference, two
ORed operational amplifiers and a current source
(Figure 1)
Figure 1 : TSM101 Schematic Diagram
A great majority of low or medium end power
supplies is voltage regulated by using shunt programmable voltage references like the TL431
(Figure 2).
The galvanic insulation of the control information is
done by using an opto-coupler in linear mode with
a variable photo current depending on the difference between the actual output voltage and the
desired one.
A current limitation is used to protect the power
supply against short circuits, but lacks precision.
This limitation is generally realized by sensing the
current of the power transistor, in the primary side
of the SMPS.
The role of the TSM101 is to make a fine regulation
of the output current of the SMPS and a precise
voltage limitation.
The primary current limitation is conserved and
acts as a security for a fail-safe operation if a
short-circuit occurs at the output of the charger.
2 - PRINCIPLE OF OPERATION
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
through an optocoupler to the PWM controller IC in
the primary side.
The controlled current generator can be used to
modify the level of current limitation by offsetting
the information coming from the current sensing
resistor.
February 1999
The current regulation loop and the voltage limitation loop use an internal 1.24V band-gap voltage
reference. This voltage reference has a good precision (better than 1.5%) and exhibits a very stable
temperature behavior.
The current limitation is performed by sensing the
voltage across the low ohmic value resistor R5 and
comparing it to a fixed value set by the bridge
composed by R2 and R3 (Figure 3).
When the voltage on R5 is higher than the voltage
on R3 the output of the current loop operational
amplifier decreases. The optocoupler current increases and tends to reduce the output voltage by
the way of the PWM controller.
The voltage regulation is done by comparing a part
of the output voltage (resistor bridge R6, R7 and
P1) to the voltage reference (1.24V).
If this part is higher than 1.24V, the output of the
voltage loop operational amplifier decreases.
1/4
AN896 - APPLICATION NOTE
Figure 2 : SMPS Using a TL431 as Voltage Controller
The optocoupler current increases and tends to
reduce the output voltage by the way of the PWM
controller.
By enabling the TSM101 current source (pin 2) it is
possible to offset the current sensing by a voltage
equal to :
• Voff # R4 * Io with Io = 1.4mA
This offset lowers the output charge current and
this function can be used to charge two types of
batteries having different capacities. The current
source is enabled by connecting pin 2 to ground
3 - CALCULATION OF THE ELEMENTS
The charge current is regulated at 700mA (if the
charge control input is left open) or 200mA (if the
charge control input is put to ground ), allowing the
charge of two different types of batteries.
ence of this diode on the charge is negligible if the
voltage drop (0.7V) is taken into account during the
design of the charger.
The voltage at the output of the charger is :
• Vout =
R6+R7
R6
xVr
and regarding R6 and R7 :
Vref
) x R7
Vout − Vref
P1, which is a part of R6 and R7 is not considered
in this equation.
The following values are used on the application
board :
• R6 = (
• R7 = 12kΩ
• R6 = 1kΩ
• P1 = 220Ω, adjust for Voutput = 15.2V with the
battery replaced by a 1kΩ resistor
3.1 - Voltage limitation
• R10 = short circuit
The end-of- charge voltage is limited at 1.45V/cell,
this is the recommended voltage for an ambient
temperature at 25oC.
A diode is generally inserted at the output of the
charger to avoid the discharge of the battery if the
charger is not powered. This diode is sometimes
directly integrated in the battery pack. The influ-
• C3 = 100nF
2/4
3.2 - Current regulation
R5 is the sense resistor used for current measurement.
AN896 - APPLICATION NOTE
The current regulation is effective when the voltage
drop across R5 is equal to the voltage on pin 5 of
the TSM101 (assuming that the internal current
source is disabled).
For medium currents (<1A), a voltage drop across
R5 of 200mV = Vr5 is a good value, R5 can be
realized with standard low cost 0.5W resistors in
parallel.
Vr5
, R5 = 0.285Ω (four 1.2Ω resistor in
Ich
parallel)
R2 and R3 can be chosen using the following
formula :
• R5 =
• R2 = R3 x
(Vref − Vr5)
Vr5
CHARGE CONTROL
If the pin 2 is left open, the charge current is nominal
at # 700mA.
If pin 2 is connected to ground, the internal current
source is enabled, the current measurement is
off-setted by a voltage equal to :
• Vr4 = Io x R4 with Io = 1.4mA
This can be used to lower the charging current or
eventually to stop the charge, if Vr4 > Vr5
In our example, the current offset is equal to 700 200mA = 500mA, representing a voltage offset
Vr4 = 150mV across R4.
The following values are used on the application
board :
• R5 = 4 *1.2Ω 0.5W in parallel
• R4 = 130Ω
• R2 = 1.2kΩ
• R3 = 220Ω
• R9 = short circuit
• R1 = 10kΩ
• C2 = 100nF
• C5 = 100nF
• C1 = output capacitor of the SMPS
• C4 = 10µF
HIGH FREQUECY COMPENSATION
Two R-C devices (R9+C2 & R10+C3) are used to
stabilize the regulation at high frequencies. The
calculation of these values is not easy and is a
function of the transfer function of the SMPS.
A guess value for the capacitors C2 and C3 is
100nF.
Figure 3 : SMPS Using the TSM101
3/4
AN896 - APPLICATION NOTE
4 - SCHEMATIC DIAGRAM
Figure 2 represents a schematic of the output
circuit of a "classical" SMPS using a TL431 for
voltage regulation. This circuit is modified to use
the TSM101 and the final circuit is represented in
figure 3.
5 - IMPROVEMENT
In applications requiring low voltage battery charge
or when the charger is in current regulation mode,
the output voltage can be too low to supply correctly
the TSM101.
The same problem occurs when the output is shortcircuited.
A solution to provide a quasi constant supply voltage to the TSM101 is shown at figure 4 : an auxiliary
winding is added at the secondary side of the
transformer.
This winding is forward coupled to the primary
winding, the voltage across it is directly proportional
to the mains rectified voltage, even if the flyback
voltage is close to zero.
As this auxiliary winding is a voltage source, it is
necessary to add a resistor (R11) on the cathode
of the rectifier (D3) to limit the current.
A low cost regulator (Q1 and Zener diode D4) is
used to power the TSM101. This is necessary with
autoranging SMPS with wide input voltages, for
example 90 to 240V without switching.
In standard SMPS with voltage ranges from 200 to
240VAC or 100 to 130VAC, this regulator can be
removed.
Figure 4
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from
its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications
mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information
previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems
without express written approval of STMicroelectronics.
© The ST logo is a trademark of STMicroelectronics
© 1999 STMicroelectronics – Printed in Italy – All Rights Reserved
STMicroelectronics GROUP OF COMPANIES
Australia - Brazil - Canada - China - France - Germany - Italy - Japan - Korea - Malaysia - Malta - Mexico - Morocco
The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A.
© http://www.st.com
4/4
sTANDARD LlNEARlCs
玩
sCsⅡtHo"s0Ⅱ
CS
甄]GR⑥ EL匣 C稠 ⑥变Ⅱ
Type
TSM101ACD
TSM101ACN
TSM101AlD
TSM101AlN
TSM101CD
TsM101CN
D
TSM101IN
TsM221ID
TsM2211N
TsM101丨
MlXED PART
Descr∶ ption
Vo"age and current contro"er
Vo"age and current contro"er
VoⅡ age and current contro"er
Vo"age and Current contro"er
VoⅡ age and Current Contro"er
Vo⒒ age and current contrOIler
Vo"age and current contro"er
Vokage and Current contro"er
DuaI CMOs operatonal AmpⅡ Ⅱer
Dual CMOS Opera刂 onal AmpliⅡ ρr
Temper早
刂
1;;e range
-20to70
-20to70
-40to125
-40to125
-20to70
-20to70
-40to105
-40to105
-40to125
-40to125
Package
so8
DIP8
S08
DlP8
So8
DlP8
s08
DlP8
s014
DIP14
旒矗矗腽麒
蜕 磊
APPLICATlON NOTE
A VOLTAGE SUPERVISOR USING THE TSM101
LAFFONT
by s。
・the poskhe inputtVs)of曲 e second operator
Tbis techniCainote shows how t0usethe TsM101
(pin5)。 lowerthan1.24Ⅵ
integrated circu"to rea"ze a voⅡ age oupeMsor,
、
An example ofreaⅡ zation is given,
1ˉ
A resistor ne1work(R1,R2,R3)is used to bias the
input ofthe mo operak)rs,when the input voltage
is out ofthe"mⅡ s,the output(pin6)is c|ose to zero.
TsⅢ 101PREsENTATION
The TsM101integrated Circu"lncorporates a high
stab""y series band gap vo"age reference, two
ORed ope【蕊 ona|amp丨 ifiers and a current source
(Figure1).
Figure1:TSM101schematic Diagram
This signal can be used dired丨 y to power an optoˉ
Coup丨 eL
In our appⅡ cation,we have added atrans∶
stor(Q1),
This transistoris driven Via a zener diode(D1).
・
This Cirouit has two advantages∶
廿1is zener diode avoids problems encounˉ
supeMsors∶ 、
″hen the
supply vo"age is丨 owerthan the operating vO|tˉ
age ofthose cirouits,the behavioris erratic,
1ˉ
tered、 ″ith:η any voⅡ age
The minimum operaJng vokage ofthe TsM1o1is
5V WⅡ ha4.7V zener diode,the transistor Q1wi丨
8
than5V whateverthe output ofthe TsM101,
2
7
2-the optocoupIeris ON Only r the input vo"age
3
6
1
is inside the specified range.
3ˉ
5
4
|
never be saturated if the supp丨 y vo"age is|ower
CALCuLAT∶ oN OFt"E ELEⅢ E"Ts
Let assume∶
・Vmh.〓
m∶ nimum
mreshold voⅡ age
●Vmax.=ma刈 mum thresho|d voItage
●Vcc〓 non∩ ina丨 vo"age
2ˉ
PRlNC∶ PLE0F
OPERAT:o"^ND
sCHEⅢ ATIC DIAGRAⅢ
We have the1o丨 丨
owing equations∶
v5〓
The Mo operationa|ampⅡ Ⅱers are used as compaˉ
rators.
v7〓
The firstoperator has its+inputwiredtothe intemal
1.24V reference and the second one itsˉ input
Ⅲ
Wired to1.24Ⅵ
As the two operators are ORˉ ed intemally,the
output(pin6)is|。 w盯
・the
:
(Vmin.x(R1+R2》
(Vnlax.XR1)〓
‘
〓v,ef
vref ∷ⅡⅡ ¨Ⅱ
。
=髯
R2〓
⊥言
-hi
甘〓
|嚣
:巳
negatˇ e input(VO ofthe】 rst operator
(pin7)is higherthan1,24V
-
AN89s/0497
1`2
APP凵 CATION NOTE
Examp丨 e∶
then∶
supervision of a12V+ˉ
5°/。 p° wer
suppIy∶
● R1〓
・Vmin.〓 11.4V Vmax.〓 12.6V
2,36ko
● R2=200Ω
Wetake R∑ =24kΩ lsO0uA in the res⒗ tor
netˉ
workl
∷ ∶∵
● R3=21.43kΩ
∶
● R4=12kΩ
・ D1〓 4.7V zenerdk旧 e
∷
● R5〓 10kΩ
Ib(Q1)〓 500ItA when ON and a ourentof10mA
● R6〓 1kΩ
in the opto-coup丨 er
The comp丨 ete schematic ofthe voltage supemsor
When ON
is represented on Figure2。
Figure2:VoⅡ age supeMsor w"h TSM101
INPUT
TS"1⑦
1
oUTPUT
ou = 0Κ
GND
m1∶ a"o,№ wθˇθr,s0sTH0"s0N mlCr° d-nlcsassumos m mg""sIblIky
ofsuch InformatIon norfor any infringement of patonts or other"ghts ofthird ρa"les wh1ch may resu"
uon° r°thθ mIse undθ ranv patent or patθ nt"ghts of sGsˉ 1"0ⅢsON ⅢlCroeleCtronics.
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onents∶ n"fe
information ρrθ viousIy supρ
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Infonnauon仙 mIshedIs hlIOVod b be臼 CCu"Ⅱ 臼nd
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sG⒐TH0Ms0Nm℃ roelectronIcs GR0VP OF COMP^NlEs
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APP凵 CATION NOTE
AB肝 ERY CHARGER UsING THE TSM101
by s。
LAFFONT
Thistechnicalnote shows how to use theTSM101
integrated circu"W"h a sWitChing m° de power
A0reat m刽 omy of bw° r medium end power
supp丨 y(sMPS)t。
gramrnabIe vo"age references"ke the TL431
rea丨 ize
a ba⒒ ery charger.
An example ofrealizaJon of a12V Nicke卜
bauery chargeris given.
1ˉ
Cadmium
(Figure2).
The galVanic insulation ofthe controHnfo"η ation is
done by using an opt。 ˉ
couplerin Iinear mode With
a variab丨 e
photo current depending on the di矸 erˉ
ence between the actua丨 output vo"age and the
Ts"101PREsENTATION
The TsM101integrated CircuⅡ
supp"esis VoⅡ age regu丨 ated by using shunt proˉ
incorporates a high
desIred one。
stab"ity series band gap voltage reference,two
oRed operationaI ampⅡ Ⅱers and a current source
(Figure1)
揣
彗柢
::甘 %#::f1`J龈
{昆 :辟
This"mihtion is genera"y rea"zed by sensing the
current Of the power transisto1in the primary side
ofthe`莼
sMPs,
Figure1:TsM101SChemaⅠ c Diagram
The rOIe ofthe TSM101isto make a Ⅱne regula刂 on
ofthe output current of the sMPS and a precise
voⅡ age lirn"auon。
。
The primary current丨 irnitation is conserved and
acts as a security for a fa"ˉ safe operation if a
shod-CirCu"occurs atthe output ofthe Charger.
8
2ˉ PR∶ NCIPLE
7
OF oPERATION
The currentregu丨 ation Ioop and the vo"age"mlaˉ
tion丨
6
oop use an interna11.24V bandˉ gap vo"age
reference.This vo丨 tage reference has a good preˉ
Cision(betterthan1,5%)and exhibits a very stable
temperature behavio∴
5
The current Ⅱmitation is perfor:η ed by sensing the
Vo"age across thelow ohrniC Va丨 ue resistor R5and
compaHng "to a fixed v。 lue set by the bridge
composed by R2and R3(Figure3).
This丨
C)Comparesthe DC Vo"age and the current
丨
eve|at the output of a sWitching power supp丨
y to
an internaI reference.k provides a feedback
through an optocouplertothe PWM controller丨
C in
The contro"ed Current generator can be used to
Ⅱn∩ itation by offse‖ ing
m。 dify the IeVel of current
the info"η ation corning from the current sensing
AN89G/0497
amp丨 ifier decreases. The optocoup|er Current inˉ
creases and tendsto reduCe the output vo"age by
the way Ofthe PM/l Contro"e∴
The vo丨 tage regu丨 ation is done by comparing a part
the primary side.
resisto∴
Whenthe vo"ageon R5is higherthan the VOItage
on R3the output of the0urrent|oop operationaI
of the output voItage(resistor bridge R6,R7and
P1)t° the voⅡ age reference(1,24V),
If this pa"is higher than1.24V,the output ofthe
vo"age丨 oop operationa|amp|"ier decreases,
1/4
APPLICATION NOTE
Figure2:sMPs Using a TL431as Vo"age Cont:o"er
m ENs
◆¤uTpuT
The optoCoupler current increases and tends to
ence ofthis diode on the charge is neg"gib丨 e iftho
reduce the output vo"age by the、 ″ay ofthe PM/l
contro"e∴
vo"age drop(0.7V)istaken into accountdu"ng the
By enablingthe TsM101Curent source(ph2)1⒗
The vo"age atthe output ofthe chargeris∶
possib丨 e to offsetthe current sensing by a vo"age
equalto∶
・
‰Vr
%ut=骂 菇
● V。 ff#R4・ 1o WⅡ h b〓
1.4mA
design ofthe charger.
and regarding R6and R7:
This offset丨 owers the output charge current and
this funCtion can be used to charge two types of
∶
∷
・R6=气
士
弋
瓦
瓦
÷
丌
了)xR7
batteries haVing different capacities,The Current
P1,WhiCh is a partof R6and R7is not considered
sourCe is enab丨 ed by conneCting pin2to ground
in this equation.
3ˉ
The following va丨 ues are used on the app"cation
CALCULATION OF THE ELEⅢ ENTs
The charge℃ urrent is reguIated at700mA("the
charge contro|input is丨 eR open)or200mA(if the
charge contro|hput⒗ putto ground),al丨 owing the
charge oftWo differenttypes of batteries.
board:
● R7〓 12kΩ
● R6〓 1kΩ
● P1〓 220Ω ,a耐 ustfor V。 ulput〓 15.2V With the
ba∮ ery replaced by a1kΩ resistor
3.1ˉ VoItage Ⅱn△ ta刂 on
・ R10〓 short CirCuⅡ
The endˉ ofˉ Charge vo"age is lirn"ed at1.45V/ce",
∞ dv° lta∞
Γ
咒
龆 品拥 摺
?m amu涮
● C3〓
A diode is genera"y inserted at the0utput of the
3.2ˉ
100nF
Current regula刂 on
chargerto avoid the disCharge of the ba仗 ery if the
R5is the sense resistor used for current measureˉ
chargeris not powered.This diode is sometimes
ment.
direct丨
2肛
y integrated in the ba"ery pack.The inf丨
A"8o6
鲂
uˉ
・
APPLICATION NOTE
The currentregu丨 ation is effecⅡ vewhen the vo"age
ln ourexamp|e,the current o彳 setis equa丨 to7ooˉ
drop acrOss R5is equalto the vo"age on pin5of
200m``〓 500mA,representing a vo"age o矸 set
the TsM101(assumhg that the intemal current
V田
source is disab丨 ed).
The fo"owing va丨 ues are used on the appⅡ cation
board∶
For medium currents(<1A),av°
ue,R5can
be
R5of200mV〓 Vr5is a good va丨
"age
drop across
rea"zed with standard丨 ow cost0,5VV resistors in
para"e1.
・
R5〓
景,R5=0・ 2:5Ω ⒃ur⒈
半
2Ω
mosbr h
para"el)
R2 and R3 can be chosen using the fo"owing
R3X骅
● R5〓 4★ 1.2Ω 0.5W in para丨
IeI
∷
∶
● R4〓 130Ω
∷
● R2〓 1.2kΩ
● R3=220Ω
● R9〓 shod CirCuⅡ
forrnu丨 a∶
● R2〓
=150mV aCross R4.
∷
・ R1=10kΩ
・ C2〓
100nF
● C5〓
100nF
∷
∴
・ C1〓 output CapaC"orofthe sMPS
・ C4〓
CHARGE CONmoL
lfthe pin2is|eft open,the chargecurrentis nomina|
10uF
GH FREQUECV CoⅢ PENsATlON
at#700mA。
H∶
lf pin2is oonneCted to ground,the interna丨 current
TWo Rˉ C deVices(R9+C2&R10+C3)are used t°
source is enabIed, the current measurement is
stab"ize the regu丨 ation at high frequencies.The
offˉ
seued by a vokage equa丨
・ Vr4=I。
Calcu丨 atIOn
of these Values is not easy and is a
function ofthe transferfunction ofthe SMPs.
to∶
XR4W"h Io〓 1.4mA
This Can be used to|owerthe charging current or
eventua"yto stop the Charge,"Vr4)Vr5
F∶
A guess va丨 ue for the capacitors C2 and C3 is
100nF,
gure3:sMPs Usingthe TsM101
〓
〓
AN0,6
耵
●
"TRJT
s/0
APPLICATION NOTE
4ˉ
sCHEmATlc DlAGRAm
winding is added at the secondary side of the
Figure 2 represents a schematic of the output
of a” c丨 ass⒗ ar
CirCuⅡ
SMPs using a TL431for
vo"age regulatlon.This circul is modified to use
the TsM101and the finaI circu1is represented in
figure3。
PROVEmENT
揣 嘿早
J⒊ 黜 忿早
髁 品拈曲脶R⒉
曲
e刊 ybaCk
抚l毙 赀u涟:yl1Ir"ag⒐ even Ⅱ
含ξ
∶
∶
嬲 ηJ1f:Ι∮
1|:rl指 :氵 早
;瑟 h:Jξ
i滗
:∶
5ˉ ∶
Ⅲ
ln appⅡ cations requiring|ow voⅡ
age batterycharge
or when the chargeris in currentregu丨 ation了 ηode,
the outputvoltagecan betoo丨 owtosuppIyCorrect丨 y
the TSM101.
The same prob丨 emoccuIs when the outputis shortˉ
circuited.
A so丨
transforme∴
ofthe reCt"ier(D3)t°
the ourrent.
"mⅡ
A丨 oW cost regu丨 at° r(Q1and
zener diode D4)is
used to powerthe TS"l,o1.This is necessary、 Ⅳith
autoranging SMPs wⅡ h wide input vo"ages,for
example90to24OV W"hout swⅡ ching。
In standard sMPs w"h vo"age ranges from2o0to
240VAC or100to130VAC,this regu丨 ator can be
ution to provide a quasi constant supp丨
y vo"ˉ
removed。
agetotheTsM101is shoWn atfigure4∶ an auxⅢ aγ
F∶
gure4:
恤〓
吣
〓
〓
0口
"田
"aIayshˉ
4/4
AN8%
砑
凵°∝°
sGsˉ TH0"sON"ICroelec△ onIcs GROuP OF coⅢ PANlEs
Japanˉ Korθ aˉ
Braz"ˉ Canadaˉ Chinaˉ FmnCθ ˉGermanyˉ Homg κ9ngˉ
MaⅡ aˉ Ⅲorocco
^ustraIiaˉ
"alyˉ
Thailamdˉ UnIted κingdomˉ U,s.^.
The NetherIandsˉ slngaρ orθ ˉsρaInˉ swedenˉ sw"zerIand o Taiwanˉ
0匚
◎ 1θ θ7sGsˉ TH0Ⅲ sON Microdectron忆 s-Printed in ltalyˉ A"R∶ ghts ReserVed
〓凵°°
ˇer,sGsˉ TH0MsON Ⅲiσ oe∶ ectronics assumes no,esρ onsibiII″
∶
nformation仙 mIshed Is belieˇ θd to be accurato amd mII臼 ble。
"owθ
ngement of ρatents or OIherrights ofthird pa"ies which may res凵 t
forthe consequences of use of such information norfor anyinfr∶
from its use.No"censeis granted byimp"cation or othemise under any ρatθ nt or ρatentrIghts ofsGsˉ THOMsON miCroeIectronics,
specificau° m mentioned in this ρubI∶ ca刂 on are subiect t° change W∶ thou notIce,ThIs ρub"cauon supersedes and repIaces a"
information prevbusIy supp"ed。 sGsˉ THOmsON ⅢicmeIectronics products are mot authorIzed f0r use as criticaI components in Ⅱfe
thout exρ 【
ess Written approval of sGsˉTHOms0N Ⅲicg。 eleCtronics.
suppo"devices or systems vˇ ∶
q羸旒
APPLlCATlON NOTE
A LINEAR BATTERY CHARGER USlNG THE TSM1o1
by s。
This appⅡ ca刂 on not0shows an examp丨 e of Ⅱnear
2ˉ
L^FFONT
C^LCVLAW0N OF THE ELEMENTs
bauery charger using the TsM101inΙ egrated ci卜
Cu".
This Chargeris used for a six Ce"sN℃ ke卜 ∞ dmium
ba⒒ ery,
The charge current⒗ regulated at200mA(Ⅱ the
charge contro丨 input is Ie】
open)or6OmA(if the
charge contro|inputis putto ground),a丨 bwing the
charge oftWo differenttypes of batteries.
1~Tsm1o1PREsENTATlON
2.1ˉ Vo∶ tage"mitat∶ o"
The endˉ ofˉ Charge vo"age is Ⅱ
mited at1.45V/ce|1
this is the recon1Fη ended vo"age for an ambient
temperature at25° C,
D5avoidsthedisChargeofthebaueryifthecharger
is not powered。 This diode is sometimes direct丨 y
integrated in the battery pack,The inf|uence ofthis
diode on the chargeis negⅡ gib|eifthe v0"age drop
(0.7V)istaken into accountduringthedesign ofthe
The TSM101integrated circu"inCorporates a high
charger.
stabⅢ ty
The vo"age,on the emi∮ er oftransistor Q1is
se"es band gap vo"age reference,two
oRed operational amp"fiers and a current source
(Figure1)。
The contro"ed current generator can be used to
Veq1〓 (⒈ 45X6)+0.7V=9,4V
and R7∶
〓
臀
and,regarding R6
γd
modify the丨 eve丨 of current"m砣 ation by offse∮ ing
铷
the inforrη ation
P1,which is a partof R6and R7is not considered
coming from the current sensing
reslstor.
F∶
in this equation.
gure1:TsM101SchemaⅡ C
The fo"owing values are used on the appⅡ cation
Diagram
board∶
・ R7〓 10kΩ
∷
・ R6〓 1.5kΩ
●P1 〓220Ω ,
a丬 ust for V。 utput=8.7V(° n the
cathode of D5)w"h the ba⒒ery replaced bya1kΩ
1
8
resistor
● R10=sho"CirCuⅡ
100nF
2
7
・C3〓
3
6
2.2 Curentregulat∶
4
5
ment.
on
R5is the sense resistor used for current measureˉ
The currentregu丨 ation is e彳 ectivewhen the vo"age
drop across R5is equalto the vo"age on pin5of
the TsM101 (assuming that the interna丨
current
source is disab丨 ed).
For medium currents((1A),a、 °Ⅱ
age drop across
R5of200mV=Vr5is a good Va丨 ue, R5can be
AN8970497
〃3
APPLICATION NOTE
reaⅡ zed
W1h standard Iow cost O.5VV resisto1or
3ˉ
POWER TRANsIsTOR sELECTION
W"h Mo0.25、 ″ resistors.
R2 and R3 Can be chosen using the fo"owing
The output voⅡ age(and by consequehce,the curˉ
formuIa∶
a safe current contro1 even in case of charger
R2〓 R3/￡
些
亠
单
诟≡
:当
ˇ
rent)folloWs the Ts"li O1output(pin6).To provide
shod-CirCuit, it is neCessary to compensate the
vo"age drop on the ORing diodes integrated in the
TsM1O1.
The output voⅡ age ofthe TSM1o1can’ tbe equa丨
CHARGE CONTROL
to zero and to overcome this vo"age,the best
lfthepin2is|eR open,the ChargeCurrentis nominal
at#200mA.
lf pin2is conneCtedto ground,the interna|current
混刂
:R:∫ :潆 ￡
忐糨Fl甲 l乩 遢勰 牒
app"cation.
source is enabled, the current measurementis
Q2 is a |ow cost genera丨
se⒒ ed by a vo丨
oⅡ ˉ
transistor,
V浒
=丨
。XR4W"h
tage equa|to∶
lo=1.4mA
Q1 is a medium power transisto1 heatˉ sinked,
This Can be used to|owerthe charging current or
eventua"yto stop the Charge,if Vro>\`r5
ln ourexamp|e,the current o彳 setis equalto
capab丨 e to dissipate a feW Wausin the、 ″orst case
(output°fthe charger shodˉ ci⒑ uⅡ ed),a” c丨 assicaF’
BD135is a good examp丨
200ˉ 60mA=140mA,representing a vo"age o彳 set
4ˉ Ⅲ
board∶
tion board,
0.5W
A sma"9VAC transformeris used forthe appIicaˉ
Others components are the fo"owing∶
R11=1kΩ
・ R4〓 140Ω
・ R2〓 1.2kΩ
C5〓 100nF
C1〓 470uF
∷
・ R3〓 220Ω
・ R9=short CircuⅡ
R1=10⒑
C2〓 100nF
C5=100nF
R8=10⒑
∷
C4〓 10uF
∷
D1.¨
scHEmAT∶ c DIAGRAm
〓
〓
②θ ^"g,●
e.
IsCELLANEOUs COMPONE盯 s
VrzI=140mV across R4.
The fo"owing va丨 ues are used on the app"cation
・ R5〓 1Ω
purpose sma" power
鲂
.D5=1N4004
。
∷
APPL∶ CATION
PRlNⅡ D ClRCUΓ
NOTE
(notto scale)
Γ chaρ 0。 c° ntρ 0l
nci∩
nci∩
+BnTTERΥ
口BnTTERΥ
Ts"10:n:
●
00°
◎ 1997sGsˉ tⅡ oMs0N ⅢiCrodedron℃ s-Printed∶ n∶ talVˉ
∝凵 0∝0
^"Rights ReserVed
sGsˉ T"oⅢ s0"mlcrooloc△ onics GROuP OF CoMP^NlEs
CCo
Australlaˉ Braz"ˉ Canadaˉ ChInaˉ F旧 nCθ ˉGθ manyˉ Hong KOmgo"alyˉ Japanˉ κorθ a o"aIaVshˉ Ma∶ taˉ
TaIwanˉ Tha"andˉ unlted κ】
ngdomˉ u。 s。"or°
Tho"ethe"andsˉ sIngaρ oreˉ spaInˉ swedenˉ swiLθ
"andˉ
^,
姘
AN抄 7
〓凵
Informatlon仙 mIshθ d ls bθ lleVod to be臼 CCurato a"d reIlable。 HoWθ ˇer,sGsˉ TH0Ⅲ s0N"Iσ ∞ ledronlCs assumos no osponglbIlI~
forthe consequences of usθ of suCh Informauon n° rf° r anylnfringement of ρatents or otherr∶ ghts ofthird ρarties which may res10t
from its use.Nb"censθ :s granted bylmρ ⅡcatIOn or othemIse undθ r anV ρatθ nt or patont Ⅱghts ofsGsˉ THOMs0N microelectronics.
specifiCation mentionθ d in th18ρ ublICa￡ lon aro εubiect t° chango WIthout noticθ 。This pubⅡ Cat:on supersedes and replaces a"
Ⅱfe
information prevbusly supplied.sGsˉ TH0Ms0N mIcmelectronics products are not authorized for use as critical componemts in
support deviCes or systems without expIess WrⅢ bn approval of sGsˉ TH0msoN ⅢiCIOelectronics.
3/s
q磊蕊
APPLlCATION NOTE
A THERMOSTAT USING TSM101
by R,LlOU
This teChnica丨 note shows how to use the TSM101
F∶
gure1:
TsM101schemauc Diagram
integrated circuit to rea"ze a sirnpIe Thermostat
cations.
contro"ing a fanin co°
"ng appⅡ
An example ofrea"zation is given with the Correˉ
sponding ca丨 cu|ations.
TsM101pREsENTAWON ~∵
The TSM101integrated circuⅡ
ˇ
^
ˉˉ∶
・ˉ
incorporates a high
θ
;tI;1Ⅰ l旯 ∫。锱
:∶ 、:早 叨 淠黯 泔 :fI∶ 【
摭
瑚
operationa丨 amp"fiers and a current sourCe
(1.4mA)as sh。 wnon F℃ ure1・
栲
揣
禺蜇 勰
岁
1鼠 薪
恝
瞿
烈
刂
APP凵 CATlON CONTEXT a"d PRINClPLE OF
oPERAT∶ oN
瑟
and endosed Volume.As an examp丨 e,the TsM101
canbeusedinsuchappⅡ cationsforMOtherBoards
coo|ing,orin SMPS(Sw"ch M° de PoWer supˉ
F∶
guⅡ e2:
Basic TherFlostat Function
pⅡ es).
This The田 nostatisto be used in association vⅥ th a
temperature sensorlex LM33sl.One Operational
amp丨 iⅡ er
of the TsM101 compares the vo"age
ofthe system.
An improvementis shown on figure3Where the
current source is used to supp丨 y the Temperature
sensorlW"h1・ 4mAcathode current),Th⒗ requires
:l∶
‖
1:胼 lr:盥 :l茫
黥 瑟 刂黼
}∶
tf∶
temperature sensor。
AN921/0597
1/3
APPLICATlON NOTE
F∶
gure3:
The lnterna丨 Current sourCΘ Can
Supp丨 y the Temperature Sensor
CALCuLATlON OF THE ELEⅢ ENTs
The fo"owing ca|cuIations app丨 yto an OVercu盯 ent
and ovedemperature Fan COntrd丨
Temperature Con"ol:
er(Ⅱ gure4).
~
The temperature upper Ⅱmitis dete"η ined by the
resistor bHdge R1/R2.
・Vref〓
Vsensor(T9xR2/(R1+F砭 扌
Ifthe sensoris an LM335,thenthe vo"age仙 nCtion
of the temperature is a direct translation of the
temperaturein Ke丨 Vin degrees fo"oWing∶
・V(T0〓 T° K)/100.
(°
As an examp|e,at25° C,the outputvo丨tage ofthe
LM335is(273+25)/100=2.98V.
Letus assume that an acceptab丨 e uppertemperaˉ
m】 is50° C,therefore∶
ture Ⅱ
●1.24〓 3.23XR2/(R1+R2)With R1+R2・ =30kΩ
as a good CompK冫
An otheri了 npr0Vementcan
be achievedfor sw"ch
Mode Powersupp丨 ies(sMPS)where"is usefu丨 to
startthe coo"ng deVice as soon as thetemperature
is too high OR When the overa"currentis above a
rη
ise precision/consumption.
● R2〓 12kΩ ,R1〓 18kΩ starts the fan at50° C,
・C1〓 0.1uF stab"izes the LM335output.
・ R=10kΩ supp"esthe LM335.
preset Ⅱ
mit(the coo"ng deVice Can thereforeantic卜
pate on the temperature e丨 evaton),Thisis shoWn
Curmnt ControI:
on figure4wherethe drop vo"ageacrossthe sense
The current |innit is deterrnined by the resistor
resistor R8is Compared to a set Ⅱmit given bythe
bridge R6/R7and the sense resistor R8。
resistor bridge R6/R7.丨 n this cOnⅡ guration,the fan
motor is started e"her by an overtemperature,or
by an oVerCurrent.
F∶
gure4:
ln many app"cations where"is necessaγ to reˉ
oW,a Common current
scale is in betWeen1and10amps.
duce temperature vvith airf丨
An Overcurrentand Overtemperature Fan Control
l
刂
I L°
l
丨
+l
l
I
l
^"92I
轿
m
|莹
:
害
荸
亨
蓍
APPLICATION NOTE
/
determined
by R3:when Q1is ON,the negative input voⅡ age
Let us assume that TsM101 is used as a the曰 ηoˉ
The hysteresis on the temperature⒗
stat for an app"cation WhiCh has a rnaxirnum conˉ
sumption of10A and requires airfloW starting at a
ofthe operationa|amp|ifier is pu"ed up;when itis
oF只 the negative inputis pu"ed d。 wn.To rnake a
current consump"on of2A,
hysteresis, a diode is inse"ed in
ordertO achieve hysteresis when
unidireCtiona丨
The vokage drop through the sense resistor R8is
series、 ″ith【 R3in
given by∶
R1not
thefan o oN,R3must be greaterthan R2〃
・Vdrop〓 Vrefx R7/(R6+Rη
to o矸 setthe
rneasurement ofthe temperature senˉ
At10A,a tolerab丨 e VoⅡ age drop can b0chosen as
sor.
50mV,therefore,the Vokage drop correspondingto
・R2〃 R1〓 R1xR2`(R1+R2)=7,2kΩ 二Req
2A is10mV.
Let us assume thatthe precision ofthe temperature
contro"sin the range of+/ˉ 1cC,andthat we expect
a5°C hysteresis,
●0.01〓 1.24XR7/(R6+R7)Where R6+R7~
1.2kΩ tO ensure proper charge for the vo"age
reference.
on the input(pin7)。 fTsM101,1℃ Coresponds
to10mVx R2/(R1+R2)〓 4mⅥ therefore,5° C wⅢ
∷
● R7〓 10Ω ,R6〓 1.2kΩ
The sense resistor R8deterFη ines the upper curˉ
correspond to Vhyst〓 20mV.
owing∶
mitfo丨 丨
rent Ⅱ
The resistor R3shouId have an inf丨
・Vdrop〓
R8XlmaX
on pin7,fo"oWing the equation∶
X Req/(R3+Req)〓 Vhyst
● R3=4,3MΩ
●VCC
● R8=5n“ 冫
Motor Con"d:
the base curentto10mA,R4
noise due to the Fnotor.
shou|d be Chosen in the range of1kΩ .The pu"up
resistor R5Can be chosenin the range of10⒑
。
The capac"ors C2and C3stab"i立 e respective丨 ythe
command of the power transistor and fi"er the
The powertransistor Q1 is contro"ed via its base
resistor R4.To limⅡ
uence of20mV
p
,
● R4〓 1kΩ ,R5〓 10kΩ
巍
蟓
￡
:黜
祝扌品
:∵ :%Ⅱ
-
H:gem"d
崽
⒊
Ⅲ
:l衤 s%猊 甜
甜铞⒒
ρ
吊
er any
g"sd""d mⅢ es蹦 ch may灬 毗
den‘ or￠ hσ Ⅱ
ρ
ghts ofsGs=T"oMsON MiCroθ
atenI or patθ
Iθ
弼
斟
擀
珲 i§ 槲
鳓
骟
鞲
硼
槲
胛
辑邋
瑙
ghts ReserVed
Ⅲicroelec饣 onics GRoVP OF ComP^NlEs
sGsˉ
Japanˉ Koreaˉ ⅢaIayshˉ MaⅡ aˉ Morocco
BrazⅡ ˉCanadaˉ Chinaˉ Fra"ceˉ Gθ rmanyˉ Hong κongˉ
"aIyˉ
Tha"andˉ V"1tbd κIngdomˉ U。 s。
singaporeˉ spainˉ swedenˉ swItzo"andˉ TaIWanˉ
The Nethθ
^ustra"aˉ
^.
"andsˉ
^"s21
钫
∝凵°∝0
^ll R∶
TH0ms0N
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