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TIMING REQUIREMENTS

R

DELAY

TPIC9201N

SLIS115 – JULY 2005

T

PARAMETER

MIN

TYP

MAX

UNIT

SPI frequency

4

mHz

T1

Time from NCS falling edge to CLK rising edge

10

ns

T2

Time from NCS falling edge to CLK falling edge

80

ns

T3

Time for CLK to go high

60

ns

T4

Time for CLK to go low

60

ns

T5

Time from last CLK falling edge to NCS rising edge

80

ns

T6

SDI setup time before CLK edge

10

ns

T7

SDI hold time after CLK edge

10

ns

T8

Time between two words for transmitting

170

ns

The external capacitor is selected to provide a delay time based on the current equation for a capacitor, I = C

dv/dt and a 28 µA typical output current.

Therefore, the user should select a 47-nF capacitor to provide a 6 ms delay at 3.55 V.

I = C dv/dt

28 µA = C

× (3.55 V / 6 ms)

C = 47 nF

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