PCA2000 datasheet(10/19 Pages) PHILIPS

10 / 19 page

2003 Dec 17

Philips Semiconductors

Product speciﬁcation

32 kHz watch circuit with programmable

adaptive motor pulse

PCA2000; PCA2001

handbook, full pagewidth

MGW356

VDD

VP(mod)

VDD(mod)

VSS

VP(start)

tp(start)

t1 t1 t1

tstore

Vstore

Vpre-store

tpre-store

Fig.7 Supply voltage modulation for programming.

Checking memory content

The stored data of the OTP array can be checked bit wise

by measuring the supply current. The array word is

selected by the instruction state and the bit is addressed

by the shift register.

To read a word, the word is first selected (pulse

distance t1), and a logic 1 is written into the first cell of the

shift register (pulse distance t3). This logic 1 is then shifted

through the entire shift register (pulse distance t2), so that

it points with each clock pulse to the next bit.

If the addressed OTP cell contains a logic 1, a 30 k

Ω

resistor is connected between VDD and VSS, which

increases the supply current accordingly.

Figure 8 shows the supply voltage modulation for reading

word B, with the corresponding supply current variation for

word B = 110101 (sequence: first MSB and last LSB).

PCA2000 데이터시트(PDF) 10 Page - NXP Semiconductors