TC1303C-1A1EMF
| Model | TC1303C-1A1EMF |
| Description | 0.5 A SWITCHING REGULATOR, 2400 kHz SWITCHING FREQ-MAX, PDSO10, 3 X 3 MM, 0.9 MM HEIGHT, PLASTIC, DFN-10 |
| PDF file | Total 38 pages (File size: 756K) |
| Chip Manufacturer | MICROCHIP |
TC1303A/TC1303B/TC1303C/TC1304
4.6
TC1304 Sequencing
The TC1304 device features an integrated sequencing
option. A sequencing circuit using only the SHDN input,
(Pin1), will turn on the LDO output (V
OUT2
) and delay
the turn on of the Buck Regulator output (V
OUT1
) until
the LDO output is in regulation. During power-down,
the sequencing circuit will turn off the Buck Regulator
output prior to turning off LDO output.
SHDN
V
OUT2
Enable
+
–
160 µs Delay*
92% of V
OUT2
To PG
Delay CKT.
V
OUT1
Enable
+
–
160 µs Delay*
92% of V
OUT1
* 160 µs delay on trailing edge
FIGURE 4-2:
TC1304 Sequencing Circuit.
4.7
TC1304
Power Up Timing From SHDN
V
IN1
/V
IN2
Soft Start
Both outputs of the TC1303/TC1304 are controlled
during start-up. Less than 1% of V
OUT1
or V
OUT2
overshoot is observed during start-up from V
IN
rising
above the UVLO voltage or either SHDN1 or SHDN2
being enabled.
SHDN
500 µs
V
OUT1
t
WK
+ t
S
V
OUT2
300 ms
Power Good
4.8
Overtemperature Protection
The TC1303/TC1304 has an integrated overtempera-
ture protection circuit that monitors the device junction
temperature and shuts the device off if the junction
temperature exceeds the typical 165°C threshold. If the
overtemperature threshold is reached, the soft start is
reset so that, once the junction temperature cools to
approximately 155°C, the device will automatically
restart.
FIGURE 4-3:
from SHDN.
TC1304 Power-up Timing
©
2008 Microchip Technology Inc.
DS21949C-page 23
