SMH4803A View Datasheet(PDF) - Summit Microelectronics
Part Name
Description
MFG CO.
'SMH4803A' PDF : 19 Pages View PDF
SMH4803A
Preliminary
PROGRAMMABLE FEATURES
The SMH4803A has programmable time and voltage
functions that can be fine-tuned for a wide variety of
applications. Because of this a manufacturer can use a
common part type across a wide range of boards that are
used on a common host but have different electrical loads,
power-on timing requirements, host voltage monitoring
needs, etc. This ability shifts the focus of design away
from designing a new power interface for each board to
concentrating on the value added back-end logic. Be-
cause the programming is done at final test all combina-
tions (all 128 possibilities) are readily available as off the
shelf stock items.
Pin Detect
The Pin Detect function can be enabled or disabled.
Circuit Breaker Delay
The circuit breaker delay defines the period of time the
voltage drop across RS is greater than 50mV but less than
VQCB before the VGATE output will be shut down. This is
effectively a filter to prevent spurious shutdowns of
VGATE.
Power Good Delay
The PG delay timer that controls the delay from PG1# to
PG2#, and PG2# to PG3# being asserted.
Quick-Trip Circuit Breaker Threshold
This is the threshold voltage drop across RS that is placed
between VSS and CBSENSE.
Symbol
Description
tCBD
50mV Circuit Breaker Delay (filter)
tPGD
Programmable Power Good Delay
(PG1 to PG2, PG2 to PG3)
tFSTSHTDN Fast Shut Down delay from fault to VGATE off
tCYC
Circuit breaker cycle mode Cycle time
tRST
RESET# pulse width
tPUVF
Programmable Under-Voltage filter
tPDD
Programmable Pin Detect Delay
Note: * Denotes default configuration setting
Min.
200
Typ.
400
150
50 *
5
50
250
500
1.5
5*
20
80
160
200
2.5 *
5
Off *
5
80
160
0.5
5
80 *
160
Max. Units
µs
µs
µs
µs
µs
µs
µs
ms
ms
ms
ms
ms
ns
s
s
ns
—
ms
ms
ms
ms
ms
ms
ms
2051 Prog Table 1.1
2051 4.4 3/15/01
SUMMIT MICROELECTRONICS, Inc.
10
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