PCA9509 — Datasheet Summary, Specs & Alternatives

01 — Overview

This NXP datasheet covers the PCA9509, a level-translating I2C-bus/SMBus repeater. It enables low-voltage processors to interface with standard 3.0V to 5.5V bus devices by buffering data and clock lines. Key parameters include supply voltages of 1.35V to VCC(B)-1.0V on PortA and 3.0V to 5.5V on PortB, with support for up to 400pF capacitance on the high-voltage side. The device features no external pull-up resistors required on PortA, operates at frequencies up to 400kHz, and includes lock-up-free operation to prevent bus conflicts. Available in SO8, TSSOP8, and XQFN8 packages.

02 — Key specifications

Datasheet parameters

Parameter	Min	Typ	Max	Conditions
quiescent current	250 µA	450 µA	900 µA	all port A static HIGH
output current	—	—	20 mA	mA
supply voltage range	3 V	—	5.5 V
operating temperature	-40 °C	—	85 °C
power dissipation	—	—	100 mW	mW
input capacitance	—	2 pF	3 pF	VI = 3.0 V or 0 V
output capacitance	—	6 pF	7 pF
propagation delay	69 ns	109 ns	216 ns	port B to port A; [1]
data rate	—	400 kbps	—
output voltage low	—	200 mV	300 mV	VCC(A) = > 1.35 V to (VCC(B)– 1 V); [5]
channel count	—	2	—
driver count	—	2	—
receiver count	—	2	—

03 — Alternatives

Closest matches to PCA9509

MAX3232 2.8× higher propagation delay, 2.0× higher output voltage low, 1.8× higher output current

SP3222ECA-L 9.2× higher propagation delay, 1.8× higher output current, 1.7× lower data rate

SN65HVD3082E 6.4× higher propagation delay, 3.5× higher input capacitance, 1.3× lower output voltage low

MAX485ESA 7.1× higher output current, 6.2× higher data rate, 3.6× lower propagation delay

SP481E 3.6× lower propagation delay, 2.6× higher output current, 1.6× higher operating temperature

CH340C 15.6× higher quiescent current, 5.0× higher data rate, 1.3× lower supply voltage range

04 — FAQ

Frequently asked questions

What is the channel count of the PCA9509?

The channel count is 2.

What is the data rate of the PCA9509?

The data rate is 400 kbps.

What is the driver count for the PCA9509?

The driver count is 2.

What is the input capacitance of the PCA9509?

The input capacitance is 2 pF when VI = 3.0 V or 0 V.

What is the maximum operating temperature for the PCA9509?

The maximum operating temperature is 85 °C.

What is the output capacitance of the PCA9509?

The output capacitance is 6 pF.

What is the output current specification for the PCA9509?

The output current is 20 mA.

What is the output voltage low specification for the PCA9509?

The output voltage low is 200 mV when VCC(A) = > 1.35 V to (VCC(B)– 1 V).