STMICROELECTRONICS TSM1011

TSM1011
Constant Voltage and Constant Current Controller
for Battery Chargers and Adapters
■
■
■
■
■
■
■
Constant voltage and constant current
control
Low voltage operation
Low external component count
Current sink output stage
Easy compensation
2KV ESD protection
VOLTAGE REFERENCE:
l Fixed output voltage reference
2.545V
l 0.5% and 1% voltage precision
PIN CONNECTIONS (top view)
1
Vref
Vcc
8
2
Cc-
Out
7
3
Cc+
Gnd 6
4
Cv-
Cv+ 5
DESCRIPTION
The TSM1011 is a highly integrated solution for
SMPS applications requiring CV (constant
voltage) and CC (constant current) modes.
The TSM1011 integrates one voltage reference
and two operational amplifiers (with ORed outputs
—common collectors).
The voltage reference combined with one
operational amplifier makes it an ideal voltage
controller. The other operational amplifier,
combined with few external resistors and the
voltage reference, can be used as a current
limiter.
D
SO-8
(Plastic Package)
APPLICATIONS
■
■
Adapters
Battery chargers
D
MiniSO-8
(Plastic Micropackage)
ORDER CODE
Part Number
TSM1011ID
TSM1011AID
TSM1011IS
TSM1011AIS
Temperature
Range
0 to
0 to
0 to
0 to
105°C
105°C
105°C
105°C
Package
Marking
S
D
•
•
•
•
M1011
M1011A
M802
M803
D = Small Outline Package (SO) - also available in Tape & Reel (DT
ST = Small Outline Package (MiniSO8) only available in Tape & Reel
September 2003
Revision B
1/9
TSM1011
1
PIN DESCRIPTIONS
PIN DESCRIPTIONS
SO8 & MiniSO8 Pinout
2
Name
Pin #
Vref
CcCc+
CvCv+
Gnd
Out
Vcc
1
2
3
4
5
6
7
8
Type
Function
Analog Output
Analog Input
Analog Input
Analog Input
Analog Input
Power Supply
Analog Output
Power Supply
Voltage Reference
Input pin of the operational amplifier
Input pin of the operational amplifier
Input pin of the operational amplifier
Input pin of the operational amplifier
Ground Line. 0V Reference For All Voltages
Output of the two operational amplifier
Power supply line.
ABSOLUTE MAXIMUM RATINGS
Symbol
Vcc
Vi
PT
Toper
Tstg
Tj
Iref
ESD
Rthja
Rthja
3
DC Supply Voltage
DC Supply Voltage (50mA =< Icc)
Input Voltage
Power dissipation
Operational temperature
Storage temperature
Junction temperature
Voltage reference output current
Electrostatic Discharge
Thermal Resistance Junction to Ambient Mini SO8 package
Thermal Resistance Junction to Ambient SO8 package
Unit
-0.3V to Vz
-0.3 to Vcc
0 to 105
-55 to 150
150
10
2
180
175
V
V
W
°C
°C
°C
mA
KV
°C/W
°C/W
Value
Unit
4.5 to Vz
V
OPERATING CONDITIONS
Symbol
Vcc
2/9
Value
Parameter
DC Supply Conditions
ELECTRICAL CHARACTERISTICS
4
TSM1011
ELECTRICAL CHARACTERISTICS
Tamb = 25°C and Vcc = +18V (unless otherwise specified)
Symbol
Parameter
Total Current Consumption
Icc
Total Supply Current, excluding current
in Voltage Reference.
Vz
Vcc clamp voltage
Operators
Vio
Input Offset Voltage
TSM1011
TSM1011A
DVio
Test Condition
Min
Vcc = 18V, no load
Tmin. < Tamb < Tmax.
Icc = 50mA
Typ
Max
Unit
1
mA
28
Tamb = 25°C
Tmin. ≤ Tamb ≤ Tmax.
Tamb = 25°C
Tmin. ≤ Tamb ≤ Tmax.
1
0.5
Input Offset Voltage Drift
V
4
5
2
3
mV
µV/°C
7
Iio
Input Offset Current
Tamb = 25°C
Tmin. ≤ Tamb ≤ Tmax.
2
30
50
nA
Iib
Input Bias Current
Tamb = 25°C
Tmin. ≤ Tamb ≤ Tmax.
20
50
150
200
nA
SVR
Supply Voltage Rejection Ratio
VCC = 4.5V to 28V
65
Vicm
Vicm
CMR
Input Common Mode Voltage Range for CV op-amp
Input Common Mode Voltage Range for CC op-amp
Common Mode Rejection Ratio
Tamb = 25°C
Tmin. ≤ Tamb ≤ Tmax.
1.5
0
70
60
Output stage
Gm
Transconduction Gain. Sink Current
Only1
Vol
Ios
Low level output voltage at 10 mA
sinking current
Output Short Circuit Current. Output to
Vcc. Sink Current Only
Voltage reference
Vref
Reference Input Voltage, Iload=1mA
TSM1011 1% precision
TSM1011A 0.5% precision
∆Vref
Tamb = 25°C
Tmin. ≤ Tamb ≤ Tmax.
Tamb = 25°C
Tmin. ≤ Tamb ≤ Tmax.
dB
Vcc-1.5
Vcc-1.5
85
V
V
dB
3.5
2.5
200
mA/mV
600
mV
27
50
mA
2.545
2.545
2.57
2.557
V
20
Tamb = 25°C
2.519
2.532
Reference Input Voltage Deviation Over
Temperature Range
Tmin. ≤ Tamb ≤ Tmax.
RegLine Reference input voltage deviation over
Vcc range.
RegLoad Reference input voltage deviation over
output current.
1
100
30
mV
Iload = 5mA
20
mV
Vcc = 18V,
0 < Iload < 10mA
10
mV
1) The current depends on the difference voltage beween the negative and the positive inputs of the amplifier. If the voltage on the minus
input is 1mV higher than the positive amplifier, the sinking current at the output OUT will be increased by 3.5mA.
3/9
TSM1011
ELECTRICAL CHARACTERISTICS
8
Fig. 1: Internal Schematic
Vcc
1
Vref
28V
Cv+
5
CV
Cv-
4
Out
7
Cc+
3
CC
6
Gnd
2
Cc-
8
Fig. 2: Typical Adapter Application Using TSM1011
R3
100
Vcc
1
OUT+
R2
To primary
Vref
28V
5
D
TSM1011
Cv+
R4
10K
Cv-
Load
CV
IL
4
+
3
Cc+
CC
Out
7
Rvc1
22K
2
Gnd
R5 Vsense
1K
Rsense IL
6
Cc-
+
Ric2
1K
Ric1
Cvc1
2.2nF
R1
Cic1
2.2nF
22K
OUT-
In the above application schematic, the TSM1011 is used on the secondary side of a flyback adapter (or
battery charger) to provide an accurate control of voltage and current. The above feedback loop is made
with an optocoupler.
4/9
Voltage and Current Control
5
TSM1011
VOLTAGE AND CURRENT CONTROL
5.1 Voltage Control
The voltage loop is controlled via a first
transconductance operational amplifier, the
resistor bridge R1, R2, and the optocoupler which
is directly connected to the output.
The relative values of R1 and R2 should be
chosen in accordance with Equation 1:
V ref
R 1 = R 2 ⋅  ---------------------------
V
–V 
out
Equation 1
R 5 ⋅ V ref
I lim = -----------------------------------------------( R 4 + R 5 ) ⋅ R sense
where Ilim is the desired limited current, and
Vsense is the threshold voltage for the current
control loop.
Note that the Rsense resistor should be chosen
taking into account the maximum dissipation
(Plim) through it during full load operation.
ref
P lim = V se nse ⋅ I lim
where Vout is the desired output voltage.
To avoid discharge of the load, the resistor bridge
R1, R2 should have high impedance. For this type
of application, a total value of 100kΩ (or more)
would be appropriate for the resistors R1 and R2.
For example, if R2 = 100kΩ, Vout = 4.10V,
Vref=2.5V, then R1 = 41.9KΩ.
Note: If the low drop diode is to 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 in the above calculations by replacing
Vout by (Vout + Vdrop).
5.2 Current control
The current loop is controlled via the second
transconductance operational amplifier, the sense
resistor Rsense, and the optocoupler.
The current sinking outputs of the two
transconductance operational amplifiers are
common (to the output 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.
Fig. 3: Output voltage versus output current
Vout
Voltage regulation
Current regulation
0
TSM1011 Vcc : independent power supply
Secondary current regulation
Iout
TSM1011 Vcc : On power output
Primary current regulation
R sense ⋅ I lim = V sense
V ref
V sense = R 5 ⋅ -------------------R 4 + R5
Equation 3
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 externally by a
resistor bridge tied to the Vref voltage reference.
Its midpoint 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
sense resistor, as shown in Figure 3. The
resistors of this bridge are matched to provide the
best precision possible.
The control equation verifies that:
Equation 2’
Equation 2
5/9
TSM1011
6
Compensation
COMPENSATION
The voltage-control transconductance operational
amplifier can be fully compensated. Both its
output and negative input are directly accessible
for external compensation components.
The current-control transconductance operational
amplifier can be fully compensated. Both of its
output and negative input are directly accessible
for external compensation components.
An example of a suitable compensation network is
shown in Figure 5 . It consists of a capacitor
Ccv1=2.2nF and a resistor Rcv1=22KΩ in series.
An example of a suitable compensation network is
shown in Figure 5 . It consists of a capacitor
Cic1=2.2nF and a resistor Ric1=22KΩ in series.
Fig. 4: Schematic of compensation network
Vcc
1
OUT+
D
8
Rlimit
To primary
Vcc
Vref
R2
28V
DS
5
IL
R3
100
TSM1011
Cv+
R4
10K
Cv-
Load
CV
4
+
3
Cc+
CC
Cc-
+
R5 Vsense
1K
Ric2
1K
R1
Cic1
2.2nF
22K
OUT-
START UP AND SHORT CIRCUIT CONDITIONS
Under start-up or short-circuit conditions the
TSM1011 is not provided with a high enough
supply voltage. 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 not considered
to be precise enough for the application, then a
sufficient supply for the TSM1011 has to be
ensured under all conditions. This means that it is
6/9
Rvc1
Ric1
Rsense IL
7
7
22K
Gnd
6
+
2
CS
Out
Cvc1
2.2nF
necessary to add some circuitry to supply the chip
with a separate power line. This can be achieved
in numerous ways, including an additional winding
on the transformer.
Voltage clamp
8
TSM1011
VOLTAGE CLAMP
The schematic in Figure 5 shows how to realize a
low-cost power supply for the TSM1011 (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.
Fig. 5: Clamp voltage
Vcc
Rlimit
Ivz
Vcc
Vz
TSM1011
28V
Since the Absolute Maximum Rating of the
TSM1011 supply voltage is 28V. In the aim to
protect he TSM1011 against such how voltage
values a internal zener clamp is integrated.
R limit = I vz ⋅ ( V cc – V z )
7/9
TSM1011
9
PACKAGE MECHANICAL DATA
PACKAGE MECHANICAL DATA
SO-8 MECHANICAL DATA
DIM.
mm.
MIN.
MAX.
MIN.
A
1.35
1.75
0.053
0.069
A1
0.10
0.25
0.04
0.010
A2
1.10
1.65
0.043
0.065
B
0.33
0.51
0.013
0.020
C
0.19
0.25
0.007
0.010
D
4.80
5.00
0.189
0.197
E
3.80
4.00
0.150
e
TYP
inch
1.27
TYP.
MAX.
0.157
0.050
H
5.80
6.20
0.228
0.244
h
0.25
0.50
0.010
0.020
L
0.40
1.27
0.016
0.050
k
ddd
8˚ (max.)
0.1
0.04
0016023/C
8/9
PACKAGE MECHANICAL DATA
TSM1011
10 PACKAGE MECHANICAL DATA
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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.
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© 2003 STMicroelectronics - All Rights Reserved
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