TEA1541P PHILIPS [NXP Semiconductors], TEA1541P Datasheet - Page 7

• Manufacturer Part Number: TEA1541P
• Description: SMPS control IC with synchronization function
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
6.1
Initially, the IC is supplied by the rectified mains voltage at
pin VIN. When the voltage at pin V
voltage for VIN current trip level V
current drawn from pin VIN, (I
I
current at pin VIN changes to the high value I
When the voltage at pin VIN is below the mains
voltage-dependent operation-enabling level (M-level), the
IC supply capacitor C
start-up current source to approximately 5 V. When the
voltage at pin VIN exceeds the M-level, the start-up
current source continues to charge C
see Fig.2).
When V
IC switches to high efficiency (green function) operation by
no longer drawing current from pin VIN (see Fig.5).
At V
the voltage across the auxiliary winding rises above the
voltage across C
by the auxiliary winding via pin V
If the voltage on pin V
lock-out level V
a safe restart mode in which current to the IC is supplied
by the rectified mains voltage via pin VIN, and C
re-charged by the internal start-up current source to
V
2003 Aug 11
VIN(min)
handbook, halfpage
CC(start)
(kHz)
SMPS control IC with
synchronization function
f
50
25
CC(start)
6
Start-up, mains voltage-dependent
operation-enabling level and undervoltage
lock-out
. When V
variable
CC
.
VCO
reaches the start-up voltage level V
the IC activates the external MOSFET. When
Fig.4 Multi mode operation.
CC(UVLO)
VCC
CC
synchronized operation
unsynchronized operation
rises to the V
, the IC supply current will be supplied
VCC
CC
, the IC stops switching and enters
falls below the V
is charged by the internal
VCO
fixed
VIN
) is at the low value
CC
CC(trip)(VIN)
CC(trip)(VIN)
CC
.
VCC
is below the V
(switch S1 open;
CC
level, the
, the supply
undervoltage
VIN(max)
MDB085
CC(start)
P(W)
VCC
CC
.
is
, the
7
Inhibiting the auxiliary supply by external means causes
the converter to operate in a stable, well-defined burst
mode. This is a burst standby mode that is less efficient
than the normal burst standby mode described in
section 6.12.
If the voltage at pin VIN falls below the mains undervoltage
lock-out level M
the IC stops switching.
During normal operation (non-burst standby mode), the
duty cycle of the IC, and thus the output power of the
supply, is regulated by a control voltage at pin CTRL.
If pin V
power standby operation and the start-up current drawn
via pin VIN reduces to 400 A (typical). When the voltage
on pin V
current increases to 1 mA (typical).
6.2
All internal reference voltages are derived from a
temperature compensated, on-chip bandgap.
handbook, halfpage
V CC(trip)(VIN)
V CC(start)
CC
Supply management
I VIN(max)
I VIN(min)
CC
M-level
is connected to ground, the IC switches to low
rises above 700 mV (typical), the start-up
V CC
I VIN
I CC
VIN
UVLO
Fig.5 Start-up sequence.
, a safe restart mode is activated, and
Product specification
TEA1541
MDB087