S-7750C Datasheet, PDF (4/44 Pages) Seiko Instruments Inc – PROGRAMMABLE PORT CONTROLLER (PORT EXPANDER WITH BUILT-IN E2PROM CIRCUIT)

PROGRAMMABLE PORT CONTROLLER (PORT EXPANDER WITH BUILT-IN E²PROM CIRCUIT)
S-7750C
Rev.1.1_00
„ General Description of Pin Function
1. SDA (Serial data I/O) pin
The SDA pin transmits serial data bi-directionally, is comprised of a signal input pin and a pin with Nch transistor open
drain output. 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 V_CCH by a resistor.
2. SCL (Input for serial clock) pin
The SCL pin is an input pin for serial clock, processes a signal at a rising / falling edge of SCL clock. Pay attention
fully to the rising / falling time and comply with specifications.
3. WP (Input for Write protect) pin
This pin performs Write Protect to E²PROM (This pin does not have a function for Write protect to the register).
Set the WP pin in V_CCH when using the Write Protect function. If not, set the WP pin to GND.
4. TIMEN (Input for timer enable) pin
This pin controls enable (“H”) /disable (“L”) / start (“L”→”H”) in the timer action (inversion of digital output due to
elapsed period). Regarding the timer action, refer to “„ Command” and “„ Condition to start timer, Port Output
and Register”. When raising VCCH and TIMEN simultaneously, set V_CCH ≥ 2.5 V.
5. CLK (Input for external clock) pin
As primary clock in the circuit action, users are able to use clock either from the internal oscillation circuit or input it
externally by option. Users can input clock from this pin in case of using external clock. If not, connect this pin to
VCCH or GND.
6. DO7 to DO0 (Digital output) pin
These pins are for the digital output port. Their values are equal to the ones of a control port register during output. Its
output inverts after; the timer starts and delay time has elapsed. Regarding the timer action, refer to “„ Command”
and “„ Condition to start timer, Port Output and Register”.
7. VSS pin
Connect to GND.
8. VCCH pin
Except for the output ports, the power supply is applied to the entire circuit via this pin. Regarding the voltage’s value
to be applied to this pin, refer to “„ Recommended Operating Conditions”.
9. VCCL pin
This pin is to apply the power supply for the output ports. Regarding the voltage’s value to be applied to this pin, refer
to “„ Recommended Operating Conditions”.
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Seiko Instruments Inc.