SI9135_11 Datasheet, PDF (9/16 Pages) Vishay Siliconix – SMBus Multi-Output Power-Supply Controller

SMBUS Specification
SMBus: The System Management Bus is a two-wire
interface through which simple power related chips can
communicate with the rest of the system. It uses I²C as its
backbone. Both SDA and SCL are bidirectional lines,
connected to a positive voltage via a pull-up resistor. When
Si9135
Vishay Siliconix
the bus is free, both lines are high. The output stages of
devices connected to the bus must have an open drain or
open collector in order to perform the wired AND function.
Data on the SMBus can be transferred at a clock rate up to
100 kHz. Si9135 is a slave with SMBus address of 0110000.
SMBUS TRUTH TABLE
State
Shutdown
Buck3 On
Buck5 On
Flyback On
Buck3, Buck5 On
Buck3, Flyback On
Buck5, Flyback on
All On
D7
D6
D5
D4
D3
D2
D1
D0
0
0
0
X
X
X
X
X
1
0
0
X
X
X
X
X
0
1
0
X
X
X
X
X
0
0
1
X
X
X
X
X
1
1
0
X
X
X
X
X
1
0
1
X
X
X
X
X
0
1
1
X
X
X
X
X
1
1
1
X
X
X
X
X
Notes:
1. Positive logic level is used.
2. X: don’t care.
SMBUS ELECTRICAL SPECIFICATION (Test Conditions: V+ = 5.5 V to 30 V, T_A = 0 °C)
Symbol
Parameter
Min
Max
V_IL
Data, Clock Input Low Voltage
- 0.5
0.6
V_IH
Data, Clock Input High Voltage
1.4
5.5
V_OL
Data, Clock Output Low Voltage
0.4
I_LEAK
Input Leakage
±1
Units
V
µA
SMBUS AC SPECIFICATIONS
Symbol
Parameter
Min
F_SMB
T_BUF
T_HD
T_SU
T_LOW
T_HIGH
T_F
T_R
SMBus Operation Frequency
10
Bus free time between Stop and Start
4.7
Data Hold Time
300
Data Setup Time
250
Clock Low Period
4.7
Clock High Period
4.0
Clock/Data Fall Time
Clock/Data Rise Time
Max
100
50
300
1000
Units
kHz
µs
ns
µs
ns
Document Number: 70817
www.vishay.com
S11-0975-Rev. D, 16-May-11
9
This document is subject to change without notice.
THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000