X9252 Datasheet, PDF (8/21 Pages) Xicor Inc. – Quad Digitally-Controlled (XDCP) potentiometer

X9252
HIGH-VOLTAGE WRITE CYCLE TIMING
Symbol
t_WC⁽⁸⁾⁽⁵⁾
Parameter
Non-volatile write cycle time
XDCP TIMING
Symbol
t_WRL⁽⁵⁾
Parameter
SCL rising edge to wiper code changed, wiper response time after
instruction issued (all load instructions)
Typ.
5
Min.
5
Max.
10
Units
ms
Max.
20
Units
µs
Notes: (1) Absolute linearity is utilized to determine actual wiper voltage versus expected voltage = [V(R_W(n)(actual))–V(R_{W(n)(expected)})]/MI
V(R_{W(n)(expected)}) = n(V(R_H)-V(R_L))/255 + V(R_L), with n from 0 to 255.
(2) Relative linearity is a measure of the error in step size between taps = [V(R_W(n+1))–(V(R_W(n)) + MI)]/MI , with n from 0 to 254
(3) 1 Ml = Minimum Increment = [V(R_H)–V(R_L)]/255.
(4) Typical values are for T_A = 25°C and nominal supply voltage.
(5) This parameter is not 100% tested.
(6) Ratiometric temperature coefficient = (V(R_W)_T1(n)–V(R_W)_T2(n))/[V(R_W)_T1(n)(T1–T2)] x 10⁶, with T1 & T2 being 2 temperatures, and
n from 0 to 255.
(7) Measured with wiper at tap position 255, R_L grounded, using test circuit.
(8) t_WC is the minimum cycle time to be allowed for any nonvolatile write by the user, unless Acknowledge Polling is used. It is the time
from a valid STOP condition at the end of a write sequence of a 2-wire interface write operation, or from the rising edge of CS of a
valid “Store” operation of the Up/Down interface, to the end of the self-timed internal nonvolatile write cycle.
(9) The recommended power up sequence is to apply V_CC/V_SS first, then the potentiometer voltages. During power up, the data sheet
parameters for the DCP do not fully apply until t_D after V_CC reaches its final value. In order to prevent unwanted tap position
changes, or an inadvertant store, bring the CS pin high before or concurrently with the V_CC pin on power up.
Test Circuit
Test Point
R_W
Force
Current
Equivalent Circuit
R_TOTAL
R_H
R_L
C_H
C_W
C_L
R_W
REV 1.4.1 7/29/03
www.xicor.com
8 of 21