STMICROELECTRONICS TEA2261

TEA2260
TEA2261
SWITCH MODE POWER SUPPLY CONTROLLER
.
..
.
..
..
.
.
POSITIVE AND NEGATIVE CURRENT UP TO
1.2A and – 2A
LOW START-UP CURRENT
DIRECT DRIVE OF THE POWER TRANSISTOR
TWO LEVELS TRANSISTOR CURRENT LIMITATION
DOUBLE PULSE SUPPRESSION
SOFT-STARTING
UNDER AND OVERVOLTAGE LOCK-OUT
AUTOMATIC STAND-BY MODE RECOGNITION
LARGE POWER RANGE CAPABILITY IN
STAND-BY (Burst mode)
INTERNAL PWM SIGNAL GENERATOR
DESCRIPTION
The TEA2260/61 is a monolithic integrated circuit
for the use in primary part of an off-line switching
mode power supply.
All functions required for SMPS control under normal operating, transient or abnormal conditions are
provided.
The capability of working according to the "masterslave" concept, or according to the "primary regulation" mode makes the TEA2260/61 very flexible
and easy to use. This is particularly true for TV
receivers where the IC provides an attractive and
low cost solution (no need of stand-by auxiliary
power supply). See application note AN376/0490
for detailed information.
BATWING DIP 16
(Plastic Package)
ORDER CODES : TEA2260 - TEA2261
PIN CONNECTIONS
IS
1
16
V CC
POWER SUPPLY
SECONDARY PULSES INPUT
IN
2
15
V+
POSITIVE OUTPUT STAGE SUPPLY
POWER TRANSISTOR CURRENT LIMITATION INPUT
POWER OUTPUT
June 1992
I MAX
3
14
OUT
GROUND GND
4
13
GND GROUND
GROUND GND
5
12
GND GROUND
ERROR AMPLIFIER INPUT (INVERTING)
E
6
11
R0
OSCILLATOT RESISTOR
ERROR AMPLIFIER OUTPUT
S
7
10
C0
OSCILLATOR CAPACITOR
OVERLOAD INTEGRATION CAPACITOR
C2
8
9
C1
SOFT-START CAPACITOR
2261-01.EPS
TRANSFORMER DEMAGNETIZATION SENSING INPUT
1/9
TEA2260 - TEA2261
SIMPLIFIED APPLICATION DIAGRAMS
Figure 1 : Master-slave Concept
AUDIO
OUTPUT
STAGE
Muting
Control
R
P1
MAINS
INPUT
Synchronization
SCANNING
DEVICE
Remote
Stand-by
P2
C
VOLTAGE
REGULATOR
Remote
Stand-by
V CC
TEA2260/61
SLAVE
TEA5170
MASTER
µP
VCC
INFRA-RED
RECEIVER
Power primary ground
Secondary ground (isolated from mains)
P 1 : Output voltage adjustement in normal mode
P 2 : Output voltage adjustement in stand-by
2261-02.EPS
PWM
Figure 2 : Secondary Regulation (with optocoupler)
AUDIO
OUTPUT
STAGE
Muting
Control
R
P
MAINS
INPUT
SCANNING
DEVICE
Remote
Stand-by
C
VOLTAGE
REGULATOR
VCC
TEA2260/61
µP
VCC
P : Output voltage adjustement
2/9
Power primary ground
Secondary ground (isolated from mains)
2261-03.EPS
INFRA-RED
RECEIVER
TEA2260 - TEA2261
BLOCK DIAGRAM
S
VCC
16
7
V+
15
INTERNAL
BIAS
-
VCC MONITORING
+
OVERVOLTAGE
PROTECTION
VREF
2.49V
7.4V
VREF (2.49V)
-
MODULATOR
LOGIC
+
PRIMARY
PULSES
POSITIVE
OUTPUT
STAGE
REGULATION
PULSES
IS
LOGIC
MODULATORS
10.3V
LOGIC
PROCESSOR
+
AUTOMATIC
BURST
GENERATION
(Max.)
14
NEGATIVE
OUTPUT
STAGE
-
REPETITIVE
OVERLOAD
PROTECTION
+
-
45µ A
-
OSCILLATOR
OUT
- 2A
(Max.)
CURRENT
LIMITATION
-
+
DEMAGNETIZATION
SENSING
+
0.6V
0.9V
-
0.15V
2.55V
SECONDARY
PULSE
9
11
10
C1
R0
C0
1
10µ A
2
8
IS IN
C2
3
4
I MAX
5
2261-04.EPS
TON(Max.) (60%)
SOFT-START
+ 1.2A
VCC
+
-1
-
E 6
+
15.7V
ERROR AMPLIFLIER
12 13
GND
ABSOLUTE MAXIMUM RATINGS
VCC
V+
Parameter
Power Supply
V16-V4, 5, 12, 13
Output Stage Power Supply
V15-V4, 5, 12, 13
Value
Unit
20
V
20
V
IOUT+
Positive Output Current (source current)
1.5
A
IOUT-
Negative Output Current (sink current)
2.5
Tj
Tstg
Operating Junction Temperature
Storage Temperature Range
A
150
o
C
-40, +150
o
C
2261-01.TBL
Symbol
Rth (j-c)
Junction-case Thermal Resistance
11
o
C/W
Rth (j-a)
Junction-ambient Thermal Resistance
45
o
C/W
* Soldered on a 35µm, 40cm2 board copper area.
MAXIMUM POWER DISSIPATION
4
P tot (W)
3
45 oC/W
2
TAMB ( oC)
0
50
100
150
2261-05.EPS
1
3/9
2261-02.TBL
THERMAL DATA
TEA2260 - TEA2261
Symbol
VCC
IOUT+
IOUTIOUT+
IOUTFoper
VIN
ROSC
COSC
C1
C2
C2/C1
Tamb
Parameter
Power Supply
Positive Output Current (source current)
Negative Output Current (sink current)
Average Positive Output Current
Average Negative Output Current
Operating Frequency
Input Pulses Amplitude (Pin 2)
Oscillator Resistor Range
Oscillator Capacitor Range
Soft-starting Capacitor Range
Overload Integration Capacitor
Ratio C2/C1 (C2 must be ≥ C1)
Operating Ambient Temperature
Min.
VCC stop
10
1.5
20
0.47
0.047
0.047
1
-20
Typ.
12
2.5
Max.
VCC max
1.2
2.0
0.6
0.6
100
4.5
150
4.7
1
1
70
Unit
V
A
A
A
A
kHz
V
kΩ
nF
µF
µF
o
C
2261-03.TBL
RECOMMENDED OPERATING CONDITIONS
ELECTRICAL CHARACTERISTICS (Tamb = 25oC, VCC =12V, unless otherwise specified)
Symbol
Parameter
Min.
Typ.
Max.
Unit
9.3
6.4
2.4
10.3
7.4
2.9
0.7
7.5
15.7
35
11.3
8.4
V
V
V
mA
mA
V
mA
POWER SUPPLY
VCC(start)
VCC(stop)
Hyst VCC
ICC(start)
ICC
VCC(max)
ICC(over)
Starting Voltage (VCC increasing)
Stopping Voltage (VCC decreasing)
Hysteresis (VCC(start) - VCC(Stop))
Starting Current (VCC = 9V)
Supply Current (VCC = 12V)
Overvoltage Threshold on VCC
Supply Current after Overvoltage Detection (VCC = 17V)
15
26
1.4
15
42
OSCILLATOR / PWM SECTION
Delta F
F
tON max
Accuracy (ROSC = 68kΩ, COSC = 1nF)
Maximum Duty Cycle in Primary Regulation Mode
10
50
60
2.34
75
550
2
0.08
2.49
%
70
%
2.64
dB
kHz
mA
µA
V
ERROR AMPLIFIER SECTION
AVO
Fug
ISC
IBE
VREF
Open Loop Gain
Unity Gain Frequency
Short Circuit Output Current (Pin 7 connected to ground)
E Input Bias Current (Pin 6)
Internal Voltage Reference (connected to error amplifier input and
not directly accessible)
INPUT SECTION
VIN
VIS
IBIN
IBIS
IN Input Threshold (Pin 2)
IS Input Threshold (Pin 1)
IN Input Bias Current
IS Input Bias Current
0.6
0.85
0.15
0.3
0.4
1.2
V
V
µA
µA
558
837
600
900
300
2.55
10
45
0.2
642
963
mV
mV
mV
V
µA
µA
µA
VIM1
VIM2
∆VIM
VC2
IDC2
ICC2
IBI(max)
4/9
First Current Limitation Threshold
Second Current Limitation Threshold
Thresholds Difference VIM2 - VIM1
Lock-out Threshold on Pin C2
Capacitor C2 Discharge Current
Capacitor C2 Charge Current
Maximum Input Bias Current (Pin 3)
2.25
2.85
2261-04.TBL
CURRENT LIMITATION SECTION
TEA2260 - TEA2261
GENERAL DESCRIPTION
system is used, in order to avoid audible noise.
The TEA2260/61 is an off-line switch mode power
supply controller. The synchronization function and
the specific operation in stand-by mode make it well
adapted to video applications such as TV sets,
VCRs, monitors, etc...
The TEA2260/61 can be used in two types of
architectures :
- Master/slave architecture. In this case, the
TEA2260/61 drives the power transistor according to the pulse width modulated signals generated by the secondary located master circuit. A
pulse transformer provides the feedback (see
Figure 1).
- Conventional architecture with linear feedback
signal (feedback sources : optocoupler or transformer winding) (see Figure 2).
Using the TEA2260/61, the stand-by auxiliary
power supply, often realized with a small but costly
50Hz transformer, is no longer necessary. The
burst mode operation of the TEA2260/61 makes
possible the control of very low output power (down
to less than 1W) with the main power transformer.
When used in a master/slave architecture, the
TEA2260/61 and also the power transistor turn-off
can be easily synchronized with the line transformer. The switching noise cannot disturb the
picture in this case.
As an S.M.P.S. controller, the TEA2260/61 features
the following functions :
- Power supply start-up (with soft-start)
- PWM generator
- Direct power transistor drive (+1.2A, -2.0A)
- Safety functions : pulse by pulse current limitation, output power limitation, over and under voltage lock-out.
Normal Mode (secondary regulation)
The normal operating of the TV set is obtained by
sending to the TEA2260/61 regulation pulses generated by a regulator located in the secondary side
of the power supply.
This architecture uses the "Master-slave Concept",
advantages of which are now well-known especially the very high efficiency in stand-by mode, and
the accurate regulation in normal mode.
Stand-by mode or normal mode are obtained by
supplying or not the secondary regulator. This can
be ordonnered for exemple by a microprocessor in
relation with the remote control unit.
Regulation pulses are applied to the TEA2260/61
through a small pulse-transformer to the IN input
(Pin 2). This input is sensitive to positive square
pulses. The typical threshold of this input is 0.85V.
The frequency of pulses coming from the secondary regulator can be lower or higher than the
frequency of the starting oscillator.
The TEA2260/61 has no soft-starting system when
it receives pulses from the secondary. The softstarting has to be located in the secondary regulator.
Due to the principle of the primary regulation,
pulses generated by the starting system automatically disappear when the voltage delivered by the
SMPS increases.
S.M.P.S. OPERATING DESCRIPTION
Starting Mode - Stand By Mode
Power for circuit supply is taken from the mains
through a high value resistor before starting. As
long as VCC of the TEA2260/61 is below VCC start,
the quiescent current is very low (typically 0.7mA)
and the electrolytic capacitor across VCC is linearly
charged. When VCC reaches VCC start (typically
10.3V), the circuit starts, generating output pulses
with a soft-starting. Then the SMPS goes into the
stand-by mode and the output voltage is a percentage of the nominal output voltage (eg. 80%).
For this the TEA2260/61 contains all the functions
required for primary mode regulation : a fixed frequency oscillator, a voltage reference, an error
amplifier and a pulse width modulator (PWM).
For transmission of low power with a good efficiency in stand-by, an automatic burst generation
Stand-by Mode - Normal Mode Transition
During the transition there are simultaneously
pulses coming from the primary and secondary
regulators.
These signals are not synchronized and some care
has to be taken to ensure the safety of the switching
power transistor.
A very sure and simple way consist in checking the
transformer demagnetization state.
- A primary pulse is taken in account only if the
transformer is demagnetized after a conduction
of the power transistor required by the secondary
regulator.
- A secondary pulse is taken in account only if the
transformer is demagnetized after a conduction
of the power transistor required by the primary
regulator.
With this arrangement the switching safety area of
the power transistor is respected and there is no
risk of transformer magnetization.
The magnetization state of the transformer is
checked by sensing the voltage across a winding
of the transformer (generally the same which supplies the TEA2261). This is made by connecting a
resistor between this winding and the demagnetization sensing input of the circuit (Pin 1).
5/9
TEA2260 - TEA2261
SECURITY FUNCTIONS OF THE TEA2260 (see flow-chart below)
- Undervoltage detection. This protection works
in association with the starting device "VCC
switch" (see paragraph Starting-mode - standby
mode). If VCC is lower than VCCstop (typically
7.4V) output pulses are inhibited, in order to avoid
wrong operation of the power supply or bad
power transistor drive.
- Overvoltage detection. If VCC exceeds VCCmax
(typically 15.7V) output pulses are inhibited. Restarting of the power supply is obtained by reducing VCC below VCCstop.
- Current limitation of the power transistor. The
current is measured by a shunt resistor. A double
threshold system is used :
- When the first threshold (VIM1) is reached, the
conduction of the power transistor is stopped
until the end of the period : a new conduction
signal is needed to obtain conduction again.
- Furthermore as long as the first threshold is
reached (it means during several periods), an
external capacitor C2 is charged. When the
voltage across the capacitor reaches VC2 (typi-
cally 2.55V) the output is inhibited. This is called
the "repetitive overload protection". If the overload diseappears before VC2 is reached, C2 is
discharged, so transient overloads are tolerated.
- Second current limitation threshold (VIM2).
When this threshold is reached the output of the
circuit is immediatly inhibited. This protection is
helpfull in case of hard overload for example to
avoid the magnetization of the transformer.
- Restart of the power supply. After stopping due
to VC2, VIM2, VCCMax or VCCstop triggering, restart of the power supply can be obtained by the
normal operating of the "VCC switch" but thanks
to an integrted counter, if normal restart cannot
be obtained after three trials, the circuit is definitively stopped. In this case it is necessary to
reduce VCC below approximately 5V to reset the
circuit. From a practical point of view, it means
that the power supply has to be temporarily disconnected from any power source to get the
restart.
SECURITY FLOW-CHART (TEA2260)
S.M.P.S.
starting
First
threshold reached
VIM1
Y
N
Y
Second
threshold reached
VIM2
N
Pulse by pulse current
limiting C 2 charged
VC2 < 2.6V
VCCmax
reached
Y
Y
N
S.M.P.S. stopping
VCC stop reached
N=N+1
N
Normal operating
C 2 discharged
Restart
number = 3
N
Y
6/9
N
Definitive
stopping
2261-06.EPS
Y
Reset C 2
discharged
TEA2260 - TEA2261
SECURITY FUNCTIONS OF THE TEA2261 (see flow-chart below)
- Undervoltage detection. This protection works
in association with the starting device "VCC
switch" (see paragraph Starting-mode - standby
mode). If VCC is lower than VCCstop (typically
7.4V) output pulses are inhibited, in order to avoid
wrong operation of the power supply or bad
power transistor drive.
- Overvoltage detection. If VCC exceeds VCCmax
(typically 15.7V) output pulses are inhibited and
the external capacitor C2 is charged as long as
VCC is higher than VCC stop. Restarting of the
power supply is obtained by reducing VCC below
VCCstop except if the voltage across C2 reaches
VC2 (typically 2.55V) (refer to "Restart of the
power supply" paragraph).In this last case, the
circuit is definitively stopped.
- Current limitation of the power transistor. The
current is measured by a shunt resistor. A double
threshold system is used :
- When the first threshold (VIM1) is reached, the
conduction of the power transistor is stopped
until the end of the period : a new conduction
signal is needed to obtain conduction again.
- Furthermore as long as the first threshold is
reached (it means during several periods), an
external capacitor C2 is charged. When the
voltage across the capacitor reaches VC2 (typically 2.55V) the output is inhibited. This is called
the "repetitive overload protection". If the overload diseappears before VC2 is reached, C2 is
discharged, so transient overloads are tolerated.
- Second current limitation threshold (VIM2).
When this threshold is reached the output of the
circuit is immediatly inhibited. This protection is
helpfull in case of hard overload for example to
avoid the magnetization of the transformer.
- Restart of the power supply. After stopping due
to VIM2, VCCMax or VCCstop triggering, restart of
the power supply can be obtained by the normal
operating of the "VCC switch" VCC switch sequency from VCCstop to VCCstart . After stopping
due to VC2 threshold reaching, the circuit is definitively stopped. In this case it is necessary to
reduce VCC below approximately 5V to reset the
circuit. From a practical point of view, it means
that the power supply has to be temporarily disconnected from any power source to get the
restart.
SECURITY FLOW-CHART (TEA2261)
S.M.P.S.
starting
Y
Second
threshold reached
VIM2
N
VCCmax
reached
N
Y
N
Pulse by pulse current
limiting C2 charged
Y
C2 charged
S.M.P.S. stopped
Normal operating
C 2 discharged
VC2 < 2.6V
VC2 < 2.6V
Y
Y
N
N
Definitive
stopping
Reset C2
discharged
N
2261-07.EPS
First
threshold reached
VIM1
Y
7/9
TEA2260 - TEA2261
TYPICAL APPLICATION (Master/slavearchitecture)
4 x 1N4007
3
BY218-600
13
270 VAC
22k Ω
3W
150µ F
385V
1k Ω
3.3
nF
22k Ω
1nF
2.2µ F
16V
6
19
9
14
BA157
10 Ω
1W
PLR811
1N4148
2.2 Ω /0.5W
P2
1k Ω
20
39 Ω
4.7k Ω
7
6
4
5
12
13
16
17
BY218-100
15
TEA2260/61
9
8
3
1
2.2µ H
1nF
82kΩ
330
1nF nF
120k Ω
2.2k Ω
1000µ F
25V
10k Ω
25V
1A
1000µ F
25V
Stand-by
control
75
kΩ
1.2nF
22k Ω
14
SGSF
344
47µ F
330
nF
330 Ω
18 Ω
BZX85-3V0
0.135 Ω /1W
BY299
2
100 Ω
10
47kΩ
100µ F
250V
BC547C
21
11
12V
0.5A
470µ F
25V
7.5V
1A
BY218-100
330µ F
25V
22
7
10µ F
16V
2
220 Ω
16W
4
6
5
TEA5170
3
2.7nF
1kV
7
8
1
560
pF
2%
47nF
1N4148
100pF
Small signal secondary ground
Power primary ground
Secondary ground (isolated from mains)
1k Ω
POUT : 140W
f
: 32kHz
Input voltage range
170VAC – 270VAC
Input DC voltage range
210VDC – 370VDC
Output power in normal mode
25W < PO < 140W
Output power in stand by mode
2W < PO < 45W
Operating frequency
32 kHz
Efficiency at full load
> 80%
Efficiency in stand by mode
> 50%
Short circuit protected
Open load protected
Long duration overload protected
Complete shutdown after repetitive default detection
Load regulation (VDC = 310V)
→ (I135 : 0.01A to 0.8A ; I25 = 1A)
→ (I135 : 0.8A ; I25 : 0.5A ––> 1A)
Line regulation
Output 135V (± 0.13%)
Output 25V (± 0.17%)
8/9
→ (210V < VDC < 370V)
→ (I135 : 0.8A ; I25 : 1A)
150pF
Sync.
input
270 Ω
TV - SET SMPS (with TEA5170)
Output 135V (± 0.18%)
Output 25V (± 2%)
135V
0.8A
P1
100k Ω
1%
6.8k Ω
2261-08.EPS
170 VAC
TEA2260 - TEA2261
I
b1
L
a1
PACKAGE MECHANICAL DATA
16 PINS - PLASTIC DIP
b
Z
B
e
E
e3
D
9
1
8
a1
B
b
b1
D
E
e
e3
F
i
L
Z
Min.
0.51
0.77
Millimeters
Typ.
Max.
1.65
Min.
0.020
0.030
0.5
0.25
Inches
Typ.
Max.
0.065
0.020
0.010
20
8.5
2.54
17.78
0.787
0.335
0.100
0.700
7.1
5.1
3.3
0.280
0.201
DIP16.TBL
Dimensions
PM-DIP16.EPS
F
16
0.130
1.27
0.050
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics 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 licence is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics.
Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all
information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life
support devices or systems without express written approval of SGS-THOMSON Microelectronics.
© 1994 SGS-THOMSON Microelectronics - All Rights Reserved
Purchase of I2C Components of SGS-THOMSON Microelectronics, conveys a license under the Philips
I2C Patent. Rights to use these components in a I2C system, is granted provided that the system conforms to
the I2C Standard Specifications as defined by Philips.
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9/9