ZHCS429J March 2012 – November 2021 UCD3138
PRODUCTION DATA
The timing characteristics and timing diagram for the communications interface that supports I2C, SMBus, and PMBus in Slave or Master mode are shown in PMBus/SMBus/I2C Timing, I2C/SMBus/PMBus Timing Diagram, and Bus Timing in Extended Mode. The numbers in PMBus/SMBus/I2C Timing arµe for 400 kHz operating frequency. However, the device supports all three speeds, standard (100 kHz), fast (400 kHz), and fast mode plus (1 MHz).
| PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | |
|---|---|---|---|---|---|---|
| Typical values at TA = 25°C and VCC = 3.3 V (unless otherwise noted) | ||||||
| fSMB | SMBus/PMBus operating frequency | Slave mode, SMBC 50% duty cycle | 100 | 1000 | kHz | |
| fI2C | I2C operating frequency | Slave mode, SCL 50% duty cycle | 100 | 1000 | kHz | |
| t(BUF) | Bus free time between start and stop | 1.3 | µs | |||
| t(HD:STA) | Hold time after (repeated) start(1) | 0.6 | µs | |||
| t(SU:STA) | Repeated start setup time(1) | 0.6 | µs | |||
| t(SU:STO) | Stop setup time(1) | 0.6 | µs | |||
| t(HD:DAT) | Data hold time | Receive mode | 0 | ns | ||
| t(SU:DAT) | Data setup time | 100 | ns | |||
| t(TIMEOUT) | Error signal/detect(2) | 35 | ms | |||
| t(LOW) | Clock low period | 1.3 | µs | |||
| t(HIGH) | Clock high period(3) | 0.6 | µs | |||
| t(LOW:SEXT) | Cumulative clock low slave extend time(4) | 25 | ms | |||
| tf | Clock/data fall time | Fall time tf = 0.9 VDD to (VILmax – 0.15) | 20 + 0.1 Cb(5) | 300 | ns | |
| tr | Clock/data rise time | Rise time tr = (VILmax – 0.15) to (VIHmin + 0.15) | 20 + 0.1 Cb(5) | 300 | ns | |
| Cb | Total capacitance of one bus line | 400 | pF | |||
Figure 8-1 I2C/SMBus/PMBus Timing Diagram
Figure 8-2 Bus Timing in Extended Mode