S-24C128C Datasheet, PDF (8/35 Pages) Seiko Instruments Inc – Write protect function during the low power supply voltage

2-WIRE SERIAL E²PROM
S-24C128C
Rev.4.0_02_H
 Pin Functions
1. A0, A1 and A2 (Slave Address Input) Pins
In the S-24C128C, to set the slave address, connect each pin of A0, A1, A2 to GND or VCC. Therefore the users can
set 8 types of slave address by a combination of A0, A1, A2 pins.
Comparing the slave address transmitted from the master device and one that you set, makes possible to select the
S-24C128C from other devices connected onto the bus.
Each A0, A1 and A2 pin has a pull-down resistor. In open, these pins are set to the same status as they are
connected to GND.
2. SDA (Serial Data Input / Output) Pin
The SDA pin is used for the bi-directional transmission of serial data. This pin is a signal input pin, and an Nch open
drain output pin.
In use, generally, connect the SDA line to any other device which has the open-drain or open-collector output with
Wired-OR connection by pulling up to VCC by a resistor (Figure 7 shows the relation with an output load).
3. SCL (Serial Clock Input) Pin
The SCL pin is used for the serial clock input. Since the signals are processed at a rising or falling edge of the SCL
clock, pay attention to the rising and falling time and comply with the specification.
4. WP (Write Protect Input) Pin
The write protect is enabled by connecting the WP pin to VCC. When not using the write protect, connect this pin to
GND or set in open.
20
18
16
14
Maximum value of 12
pull-up resistor 10
[kΩ]
8
6
4
2
0
10
f_SCL = 400 kHz
100
Value of load capacity
[pF]
Figure 7 Output Load
 Initial Shipment Data
Initial shipment data of all addresses is “FFh”.
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