L6564HTR STMicroelectronics, L6564HTR Datasheet - Page 26

• Manufacturer Part Number: L6564HTR
• Description: Power Factor Correction ICs High Volt Start Up 700V PFC 100uA 6mA
• Manufacturer: STMicroelectronics

Specifications of L6564HTR

• Product Category: Power Factor Correction ICs
• Rohs: yes
• Maximum Power Dissipation: 0.75 W
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SO-14
• Minimum Operating Temperature: - 25 C

High voltage startup generator
7
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High voltage startup generator
Figure 38
generator). It is made up of a high voltage N-channel FET, whose gate is biased by a 15 MΩ
resistor, with a temperature-compensated current generator connected to its source.
Figure 38. High voltage startup generator: internal schematic
The HV generator is physically located on a separate chip, made with BCD offline
technology able to withstand 700 V, controlled by a low voltage chip, where all of the control
functions reside.
With reference to the timing diagram of
converter the voltage on the bulk capacitor (Vin) builds up and, at about 80 V, the HV
generator is enabled to operate (HV_EN is pulled high) so that it draws about 1 mA. This
current, minus device consumption, charges the bypass capacitor connected from the V
pin (14) to ground and causes its voltage to rise almost linearly.
Figure 39. Timing diagram: normal power-up and power-down sequences
shows the internal schematic of the high voltage startup generator (HV
Vcc_OK
(pin 14)
(pin 13)
HV_EN
Vcc
0.85 mA
V
Vcc
GD
Vcc
I
HVstart
Vcc
charge
VHV
restart
OFF
ON
Vcc_OK
Rectified input voltage
Power-on
Doc ID 022960 Rev 2
15MW
Figure 39
CONTROL
HV_EN
GND
12
operation
, when power is first applied to the
Normal
8
HVS
I
charge
I
HV
Input source is removed here
14
Vcc
HV connected to bulk cap
DC- DC loses regulation here
HV connected to
rectified input voltage
Power-of f
Bulk cap voltage
t
t
t
t
t
t
AM11463v1
AM11464v1
L6564H
CC