S-24C08C Datasheet, PDF (20/33 Pages) Seiko Instruments Inc – Write protect function during the low power supply voltage

2-WIRE SERIAL E²PROM
S-24C08C (WLP PRODUCT)
Rev.1.0_00_H
 Using S-24C08C
1. Adding a pull-up resistor to SDA I/O pin and SCL input pin
In consideration of I²C-bus protocol function, the SDA I/O pins should be connected with a pull-up resistor.
The S-24C08C cannot transmit normally without using a pull-up resistor.
In case that the SCL input pin of the S-24C08C is connected to the Nch open drain output pin of the master device,
connect the SCL pin with a pull-up resistor. As well, in case the SCL input pin of the S-24C08C is connected to the tri-
state output pin of the master device, connect the SCL pin with a pull-up resistor in order not to set it in high
impedance. This prevents the S-24C08C 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 input and I/O pin
The SCL pin and the SDA pin do not have a built-in pull-down or pull-up resistor.
The WP and A2 pins has a built-in pull-down resistor. The SDA pin has an open-drain output.
The followings are equivalent circuits of the pins.
SCL
SDA
Figure 19 SCL Pin
Figure 20 SDA Pin
20