F75909
.
F75909
SMBus Level Shifter
Release Date: Dec, 2011
Version: V0.11P
Dec
, 2011
V0.11P
F75909
F75909 Datasheet Revision History
Version
Data Brief
V0.10P
V0.11P
V0.12P
Date
2011/10
2011/11
2011/12
2011/12
Page
-
-
-
--
Revision History
Data Brief
Made Clarification and Correction
Add Application Circuit
Add Electrical Characteristics
Update Block Diagram / Application Circuit
Please note that all data and specifications are subject to change without notice. All the trade marks of products
and companies mentioned in this data sheet belong to their respective owners.
LIFE SUPPORT APPLICATIONS
These products are not designed for use in life support appliances, devices, or systems where malfunction of these
products can reasonably be expected to result in personal injury. Customers using or selling these products for
use in such applications do so at their own risk and agree to fully indemnify Fintek for any damages resulting from
such improper use or sales.
Dec
, 2011
V0.11P
F75909
Table of Content
1
2
3
4
5
7
8
9
10
11
General Description
............................................................................... 1
Feature List
...................................................................................... 1
Block Diagram
.................................................................................... 2
Pin Configuration
................................................................................. 2
Pin Description
................................................................................... 3
Electrical Characteristics
........................................................................... 3
Ordering Information
.............................................................................. 5
Top Marking Specification
.......................................................................... 5
Package Spec.
................................................................................... 6
Application Circuit
................................................................................. 7
Dec
, 2011
V0.11P
F75909
1 General Description
The F75909 is a I C-bus/SMBus level shifter that translating signal voltage level of standard I C-bus or
SMBus. Port L allows a operating voltage range from 1.0 V to [V
CC(H)
-1.0 V]. The operating voltage of Port
H is range from 3.0 V to 5.5 V. When F75909 is disabled, both port L and port H I/O pins are high-
impedance.
The bus port H are compliant with SMBus I/O levels, while port L uses a current sensing mechanism to
detect the input or output LOW signal which prevents bus lock-up. Port L uses a 1 mA current source for
pull-
pull-down driver. This results in a LOW on the port L accommodating smaller voltage
swings. The output pull-down on the port L internal buffer LOW is set for approximately 0.2 V, while the
input threshold of the internal buffer is set about 50 mV lower than that of the output voltage LOW. When
the port L I/O is driven LOW internally, the LOW is not recognized as a LOW by the input. This prevents a
lock-up condition from occurring. The output pull-down on the port H drives a hard LOW and the input level
2
2
is set at 0.3 of SMBus or I C-bus voltage level which enables port H to connect to any other I C-bus devices
or buffer.
The F75909 is not enabled unless V
CC(L)
is above 0.8 V and V
CC(H)
is above 2.5 V. The enable (EN) pin
can also be used to turn the drivers on and off under system control. Caution should be observed to only
change the state of the EN pin when the bus is idle.
2
2
2 Feature List
Voltage level shifting from L-Port (1V to Vcc
(H)
-1.0V)
No external pull-up resistors required on Port L
Open-drain I/O
Lock-up free operation
High impedance bus pin when Power-off.
1
Dec, 2011
V0.12P
F75909
3
Block Diagram
PWR_L
Vdd_switch
PWR_H
PWR_L
PWR_H
Vdd_switch
Pulse
Generator
Pulse
Generator
4
Pin Configuration
V
CC(H)
H1 H2 EN
F75909
MSOP-8
V
CC(L)
L1 L2 GND
Pin Configuration of F75909
2
Dec, 2011
V0.12P
嵌入式系统
