Philips ISP1520 16. Dynamic characteristics

Philips Semiconductors ISP1520
Hi-Speed USB hub controller
Product data Rev. 03 — 24 November 2004 36 of 51
9397 750 13701 © Koninklijke Philips Electronics N.V. 2004. All rights reserved.
16. Dynamic characteristics
[1] Recommended accuracy of the clock frequency is 500 ppm for the crystal.
[2] Suggested values for external capacitors when using a crystal are 22 to27 pF.
[1] All pins are 5 V tolerant.
Table 40: Dynamic characteristics: system clock timing
Symbol Parameter Conditions Min Typ Max Unit
Reset
tW(POR) internal power-on reset pulse
width 0.2 - 1 µs
tW(RESET_N) pulse width on pin RESET_N 0.2 - - µs
Crystal oscillator
fclk clock frequency crystal [1][2] - 12 - MHz
External clock input
δclock duty cycle - 50 - %
Table 41: Dynamic characteristics: overcurrent sense timing
V
CC
= 3.0 V to3.6 V; T
amb
= − 40 ° Cto+70 ° C; unless otherwise specified.
Symbol Parameter Conditions Min Typ Max Unit
Overcurrent sense pins OC1_N to OC4_N
ttrip overcurrent trip response time from
OCn_N LOW to PSWn_N HIGH see Figure 9 --15ms
Overcurrent input: pins OCn_N; power switch output: pins PSWn_N.
Fig 9. Overcurrent trip response timing.
mbl032
V
CC
0 V
overcurrent
input
V
CC
0 V
power switch
output
t
trip
∆V
trip
Table 42: Dynamic characteristics: digital pins[1]
V
CC
= 3.0 V to3.6 V; T
amb
= − 40 ° Cto+70 ° C; unless otherwise specified.
Symbol Parameter Conditions Min Typ Max Unit
tt(HL),
tt(LH)
output transition time 4 - 15 ns