lt3579iufd-trpbf Linear Technology Corporation, lt3579iufd-trpbf Datasheet - Page 9

• Manufacturer Part Number: lt3579iufd-trpbf
• Description: Lt3579/lt3579-1 6a Boost/inverting Dc/dc Converter With Fault Protection Features
• Manufacturer: Linear Technology Corporation

STATE DIAGRAM
FAULT1 =
OVER VOLTAGE PROTECTION ON V
OVER TEMPERATURE (T
OVER CURRENT ON SW1 (I
OVER VOLTAGE PROTECTION ON SW1 (V
OVER VOLTAGE PROTECTION ON SW1 (V
IF |V
FB > 45mV (INVERTING)
FB < 1.17V (BOOST)
OUT
| DROPS CAUSING:
OR
JUNCTION
SW1
SHDN > 1.33V
> 3.4A (MIN))
SS < 50mV
V
> 165°C (TYP))
IN
IN
• ALL SWITCHES DISABLED
• I
• FAULTS CLEARED
• SS PULLED LOW
• I
• SS CHARGES UP
• SWITCHER ENABLED
• Q1 & Q2 SWITCHES
• I
• NORMAL OPERATION
• CLKOUT ENABLED WHEN
AND
FORCED ON EVERY CYCLE
FOR AT LEAST MINIMUM
ON-TIME
WHEN SS > 500mV
SS > 1.8V
> 2.3V
(V
GATE
GATE
GATE
IN
SW1
SW2
NORMAL MODE
> 16.2V (MIN))
SAMPLE MODE
SHDN < 1.33V
OFF
ENABLED
FULLY ACTIVATED
SOFT START
INITIALIZE
V
CHIP OFF
> 42V (MIN))
> 42V (MIN))
IN
OR
< 2.3V
Figure 2. State Diagram
FAULT2 = FAULT PULLED LOW EXTERNALLY (FAULT < 0.75V)
FAULT1
FAULT1
FAULT1
FAULT1
• SS CHARGES UP
• IGATE OFF
• FAULT PULLED LOW INTERNALLY BY LT3579
• SWITCHER DISABLED
• CLKOUT DISABLED
• SS SLOWLY DISCHARGES
• INTERNAL FAULT PULLDOWN
• SS CONTINUES DISCHARGING
RELEASED BY LT3579
TO GND
LOCAL FAULT OVER
POST FAULT DELAY
LT3579/LT3579-1
FAULT DETECTED
FAULT > 1.0V
SS < 50mV
SS > 1.8V
AND NO FAULT1
CONDITIONS STILL DETECTED
FAULT2
3759 SD
FAULT1
FAULT1
35791f
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