L6382D_07 STMICROELECTRONICS [STMicroelectronics], L6382D_07 Datasheet - Page 12

• Manufacturer Part Number: L6382D_07
• Description: Power management unit for microcontrolled ballast
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Application information
6
6.1
6.1.1
12/22
Application information
Power management
The L6382D has two stable states (SAVE MODE and OPERATING MODE) and two
additional states that manage the Start-up and fault conditions
Protection is a parallel asynchronous process enabled when in operating mode.
Following paragraphs will describe each mode and the condition necessary to shift between
them.
Figure 10. State diagram
START-UP mode
With reference to the timing diagram of figure 11, when power is first applied to the
converter, the voltage on the bulk capacitor builds up and the HV generator is enabled to
operate drawing about 10mA. This current, diminished by the IC consumption (less than
150µA), charges the bypass capacitor connected between pin Vcc and ground and makes
its voltage rise almost linear.
During this phase, all IC's functions are disabled except for:
●
●
As the Vcc voltage reaches the start-up threshold (14V typ.) the chip starts operating and
the HV generator is switched off.
the current sinking circuit on VREF pin that maintains low the voltage by keeping
disabled the microcontroller connected to this pin;
the High-Voltage Start-Up (HVSU) that is ON (conductive) to charge the external
capacitor on pin Vcc.
V
T
V
CC
ED
REF
>10µs
>V
&
>3V
CC(ON)
SAVE MODE
OPERATING
START-UP
MODE
V
than 100µs
CC
for more
LGI low
<V
REF(OFF)
V
CC
<V
CC(ON)
V
CC
V
<V
CC
V
REF(OFF)
< V
REF
or
SHUT DOWN
<2V
CC(OFF)
(Figure
10): the Over Current
L6382D