TL1454A_14 Datasheet, PDF (7/25 Pages) Texas Instruments – DUAL-CHANNEL PULSE-WIDTH-MODULATION (PWM) CONTROL CIRCUIT

TL1454A, TL1454AY
DUALĆCHANNEL PULSEĆWIDTHĆMODULATION (PWM)
CONTROL CIRCUIT
SLVS423 A− MAY 2002 − REVISED SEPTEMBER 2002
short-circuit protection (SCP) (continued)
The SCP time-out period must be greater than the converter start-up time or the converter will not start. Because
high-value capacitor tolerances tend to be ± 20% or more and IC resistor tolerances are loose as well, it is best
to choose an SCP time-out period 10-to-15 times greater than the converter startup time. The value of C_SCP
may be determined using Figure 6, or it can be calculated using:
C_SCP
+
T_SCP
80.3
where C_SCP is in µF and T_SCP is the time-out period in ms.
output stage
The output stage of the TL1454A is a totem-pole output with a maximum source/sink current rating of 40 mA
and a voltage rating of 20 V. The output is controlled by a complementary output AND gate and is turned on
(sourcing current for OUT1, sinking current for OUT2) when all the following conditions are met: 1) the oscillator
triangle wave voltage is higher than both the DTC voltage and the error-amplifier output voltage, 2) the
undervoltage-lockout circuit is inactive, and 3) the short-circuit protection circuit is inactive.
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)^†
Supply voltage, V_CC (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 V
Error amplifier input voltage: IN1+, IN1 −, IN2+, IN2 − . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 V
Output voltage: OUT1, OUT2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 V
Continuous output current: OUT1, OUT2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 200 mA
Peak output current: OUT1, OUT2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 A
Continuous total dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Table
Operating free-air temperature range, T_A: C suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −20°C to 85°C
Storage temperature range, T_stg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C
† _{Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and}
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: All voltage values are with respect to network GND.
PACKAGE
D
DB
N
NS
PW
DISSIPATION RATING TABLE
TA ≤ 25°C
POWER RATING
950 mW
DERATING FACTOR
ABOVE TA = 25°C
7.6 mW/°C
TA = 70°C
TA = 85°C
POWER RATING POWER RATING
608 mW
494 mW
1000 mW
8.0 mW/°C
640 mW
520 mW
1250 mW
10.0 mW/°C
800 mW
650 mW
1953 mW
15.6 mW/°C
1250 mW
1015 mW
500 mW
4.0 mW/°C
320 mW
260 mW
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