TSM1011
Constant Voltage and Constant Current Controller
for Battery Chargers and Adapters
s
s
s
s
s
s
s
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
2
3
4
Vref
Cc-
Cc+
Cv-
Vcc
Out
8
7
Gnd 6
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
s
s
Adapters
Battery chargers
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
MiniSO-8
(Plastic Micropackage)
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
Name
Vref
Cc-
Cc+
Cv-
Cv+
Gnd
Out
Vcc
Pin #
1
2
3
4
5
6
7
8
Type
Analog Output
Analog Input
Analog Input
Analog Input
Analog Input
Power Supply
Analog Output
Power Supply
Function
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.
2
ABSOLUTE MAXIMUM RATINGS
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
Value
-0.3V to Vz
-0.3 to Vcc
0 to 105
-55 to 150
150
10
2
180
175
Unit
V
V
W
°C
°C
°C
mA
KV
°C/W
°C/W
Symbol
Vcc
Vi
PT
Toper
Tstg
Tj
Iref
ESD
Rthja
Rthja
3
OPERATING CONDITIONS
Parameter
DC Supply Conditions
Value
4.5 to Vz
Unit
V
Symbol
Vcc
2/9
ELECTRICAL CHARACTERISTICS
4
ELECTRICAL CHARACTERISTICS
Parameter
Test Condition
Vcc = 18V, no load
Tmin. < Tamb < Tmax.
Icc = 50mA
T
amb
= 25°C
T
min.
≤
T
amb
≤
T
max.
T
amb
= 25°C
T
min.
≤
T
amb
≤
T
max.
T
amb
= 25°C
T
min.
≤
T
amb
≤
T
max.
T
amb
= 25°C
T
min.
≤
T
amb
≤
T
max.
V
CC
= 4.5V to 28V
65
1.5
0
70
60
TSM1011
T
amb
= 25°C and V
cc
= +18V (unless otherwise specified)
Symbol
Min
Typ
Max
1
28
1
0.5
7
2
20
50
100
Vcc-1.5
Vcc-1.5
85
30
50
150
200
4
5
2
3
Unit
mA
V
mV
Total Current Consumption
Icc
Total Supply Current, excluding current
in Voltage Reference.
Vz
Vcc clamp voltage
Operators
V
io
Input Offset Voltage
TSM1011
TSM1011A
DV
io
I
io
I
ib
SVR
Vicm
Vicm
CMR
Input Offset Voltage Drift
Input Offset Current
Input Bias Current
Supply Voltage Rejection Ratio
µV/°C
nA
nA
dB
V
V
dB
Input Common Mode Voltage Range for CV op-amp
Input Common Mode Voltage Range for CC op-amp
Common Mode Rejection Ratio
T
amb
= 25°C
T
min.
≤
T
amb
≤
T
max.
T
amb
= 25°C
T
min.
≤
T
amb
≤
T
max.
Output stage
Gm
Transconduction Gain. Sink Current
Only
1
1
Vol
Ios
Low level output voltage at 10 mA
sinking current
Output Short Circuit Current. Output to
Vcc. Sink Current Only
3.5
2.5
200
27
mA/mV
600
50
mV
mA
T
amb
= 25°C
T
min.
≤
T
amb
≤
T
max.
T
amb
= 25°C
2.519
2.532
Voltage reference
V
ref
Reference Input Voltage, Iload=1mA
TSM1011 1% precision
TSM1011A 0.5% precision
∆V
ref
2.545
2.545
20
2.57
2.557
30
20
10
V
Reference Input Voltage Deviation Over
Temperature Range
T
min.
≤
T
amb
≤
T
max.
Iload = 5mA
Vcc = 18V,
0 < Iload < 10mA
mV
mV
mV
RegLine Reference input voltage deviation over
Vcc range.
RegLoad Reference input voltage deviation over
output current.
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
Voltage and Current Control
5
VOLTAGE AND CURRENT CONTROL
TSM1011
5.1 Voltage Control
The voltage loop is controlled via a first
transconductance operational amplifier, the
resistor bridge R
1
, R
2
, and the optocoupler which
is directly connected to the output.
The relative values of R
1
and R
2
should be
chosen in accordance with
Equation 1:
R
5
⋅
V
ref
-
I
lim
= -----------------------------------------------
(
R
4
+
R
5
) ⋅
R
sense
Equation 2’
where I
lim
is the desired limited current, and
V
sense
is the threshold voltage for the current
control loop.
Note that the R
sense
resistor should be chosen
taking into account the maximum dissipation
(P
lim
) through it during full load operation.
V
ref
--------------------------
R 1 =
R
2
⋅
-
V
–
V
ref
out
Equation 1
where V
out
is the desired output voltage.
To avoid discharge of the load, the resistor bridge
R
1
, R
2
should have high impedance. For this type
of application, a total value of 100kΩ (or more)
would be appropriate for the resistors R
1
and R
2
.
For example, if R
2
= 100kΩ, V
out
= 4.10V,
V
ref
=2.5V, then R
1
= 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
V
out
by (
V
out
+ V
drop
).
P
lim
=
V
se nse
⋅
I
lim
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.
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
5.2 Current control
The current loop is controlled via the second
transconductance operational amplifier, the sense
resistor R
sense
, and the optocoupler.
V
sense
threshold is achieved externally by a
resistor bridge tied to the V
ref
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:
Vout
Voltage regulation
Current regulation
0
TSM1011 Vcc : independent power supply
Secondary current regulation
Iout
R
sense
⋅
I
lim
=
V
sense
V
ref
V
sense
=
R
5
⋅
--------------------
R
4
+
R
5
Equation 2
TSM1011 Vcc : On power output
Primary current regulation
5/9