Philips Semiconductors
ISP1520
Hi-Speed USB hub controller
8.7 Power-on reset
The ISP1520 has an internal Power-On Reset (POR) circuit.
The triggering voltage of the POR circuit is 2.03 V nominal. A POR is automatically
generated when VCC goes below the trigger voltage for a duration longer than 1 µs.
VCC
2.03 V
POR
≤ 683 µs
0V
At t1: clock is running and available.
Fig 3. Power-on reset timing.
t1
004aaa388
POR
EXTERNAL CLOCK
A
Stable external clock is to be available at A.
Fig 4. External clock with respect to power-on reset.
004aaa365
9397 750 11689
Product data
Rev. 02 — 04 May 2004
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
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