L6591 STMicroelectronics, L6591 Datasheet - Page 27

• Manufacturer Part Number: L6591
• Description: IC CTRLR PWM PROG CM HV 16SOIC
• Manufacturer: STMicroelectronics

Specifications of L6591

• Output Isolation: Isolated
• Frequency Range: 168 ~ 192kHz
• Voltage - Input: 8.7 ~ 22 V
• Power (watts): 750mW
• Operating Temperature: -40°C ~ 150°C
• Package / Case: 16-SOIC (0.154", 3.90mm Width)
• Output Voltage: 5 V
• Input Voltage: 25 V
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: SMD/SMT
• Duty Cycle (max): 50 %
• For Use With: 497-8335 - BOARD EVAL FOR L6591
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-8286

L6591
6.5
Figure 46. Hiccup-mode OCP: timing diagram (device self-supplied)
Latched shutdown
The L6591 is equipped with a comparator having the non-inverting input externally available
at the pin DIS (#2) and with the inverting input internally referenced to 4.5 V. As the voltage
on the pin exceeds the internal threshold, the IC is immediately shut down and its
consumption reduced at a low value.
The information is latched and it is necessary to let the voltage on the Vcc pin go below the
UVLO threshold to reset the latch and restart the IC. To keep the latch supplied as long as
the converter is connected to the input source, the HV generator is activated periodically so
that Vcc oscillates between the start-up threshold V
necessary to disconnect the converter from the input source to restart the IC. This operation
is shown in the timing diagram of
power dissipation approximately by three (as compared to the case of continuous
conduction) and keeps peak silicon temperature close to the average value.
LVG, HV G
OC P la tc h
PFC _S top
Vc c_ OK
Vcc
Vcc
Vcc
r esta rt
Vc c
V
C S
on
off
1.5 V
Sec on da ry di od e i s s ho rted he re
Doc ID 14821 Rev 5
Figure
47. Activating the HV generator in this way cuts its
ccON
and V
ccON
Application information
– 1 V. It is then
t
t
t
t
t
t
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