S-24CS64A Datasheet, PDF (19/44 Pages) Seiko Instruments Inc – 2-WIRE CMOS SERIAL E2PROM

Rev.3.3_00
2-WIRE CMOS SERIAL E²PROM
S-24CS64A
„ Using S-24CS64A
1. Adding a pull-up resistor to SDA I/O pin and SCL input pin
Add a 1 to 5 kΩ pull-up resistor to the SCL input pin^*1 and the SDA I/O pin in order to enable the functions
of the I²C-bus protocol. Normal communication cannot be provided without a pull-up resistor.
*1. When the SCL input pin of the E²PROM is connected to a tri-state output pin of the microprocessor,
connect the same pull-up resistor to prevent a high impedance status from being input to the SCL
input pin.
This protects the E²PROM from malfunction due to an undefined output (high impedance) from the tri-
state pin when the microprocessor is reset when the voltage drops.
2. I/O pin equivalent circuit
The I/O pins of this IC do not include pull-up and pull-down resistors. The SDA pin is an open-drain output.
The following shows the equivalent circuits.
SCL
SDA
Figure 21 SCL Pin
Figure 22 SDA Pin
Seiko Instruments Inc.
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