S-34C02A Datasheet, PDF (21/34 Pages) Seiko Instruments Inc – 2-WIRE CMOS SERIAL E2PROM FOR DIMM SERIAL PRESENCE DETECT

2-WIRE CMOS SERIAL E2PROM FOR DIMM SERIAL PRESENCE DETECT
Rev.1.2_00
S-34C02A
„ Using S-34C02A
1. SDA I/O pin and SCL input pin
In consideration of I²C-bus protocol function, the SDA I/O and SCL input pins^*1 should be connected with a pull-up
resister of 1 to 5 kΩ.
The S-34C02A cannot transmit normally without using a pull-up resistor.
*1. In the case that the SCL input pin of the S-34C02A is connected to the tri-state output pin in the master device,
connect the SCL pin with a pull-up resistor as well in order not to set the SCL input pin in high impedance. This
prevents the S-34C02A from error caused by an uncertain output (high impedance) from the tri-state pin when
resetting the master device during the voltage drop.
2. Equivalent circuit of I/O pin
Each input pin (A0, A1, A2, WP) of the S-34C02A has a built-in pull-down register. The SDA line has an open-drain
output. The followings are equivalent circuits of the pins.
SCL
SDA
Figure 19 SCL Pin
Figure 20 SDA Pin
Seiko Instruments Inc.
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