AMC6821-Q1 Datasheet, PDF (5/54 Pages) Texas Instruments – INTELLIGENT TEMPERATURE MONITOR AND PWM FAN CONTROLLER

AMC6821-Q1
www.ti.com ...................................................................................................................................................................................................... SBAS475 – JUNE 2009
DEVICE INFORMATION
SSOP-16
(body size: 5mm x 4mm)
PWM-OUT 1
TACH 2
OVR 3
NC 4
GND 5
V_DD 6
THERM 7
FAN-FAULT 8
AMC6821
16 SCLK
15 SDA
14 SMBALERT
13 A0
12 A1
11 PWM-MODE
10 IN+
9 IN-
NAME
PWM-OUT
TACH
OVR
NC
GND
V_DD
THERM
FAN-FAULT
IN–
IN+
PWM-MODE
A1
A0
SMBALERT
SDA
SCLK
Table 1. TERMINAL FUNCTIONS
NO.
DESCRIPTION
1
Digital output, open-drain. PWM output to control fan speed.
2
Digital input. Fan tachometer input to measure the fan speed.
3
Digital output, open-drain, active low. Goes low when temperature reaches the critical shutdown
threshold or remote temperature sensor failed. (See the Interrupt section for details.)
4
Not connected. Reserved for manufacturer's testing.
5
System ground
6
Power supply, 3 V to 5 V
Digital input/output (open-drain). As an output, an active low output indicates the temperature over the
7
THERM temperature limit. As an input, the pin provides an external fan control. When the pin is pulled
low by external signal, the THERM-IN bit is set, and the fan is set to full-speed.
8
Digital open-drain output. Goes low when a fan failure is detected.
9
Negative analog differential input. Connected to cathode of external temperature-sensing diode.
10
Positive analog differential input. Connected to anode of external temperature-sensing diode
Pentium-IV™ substrate transistor or general-purpose 2N3904 type transistor.
PWM mode selection. When tied low (GND), the high PWM frequency range (1 kHz to 40 kHz) is
11
selected. When tied to V_DD or floated, the low PWM frequency range (10 Hz to 94 Hz) is selected.
Checked only on power-up or reset.
12
Device slave address selection pin (see the SMB Interface section for details). Checked only on
power-up or reset.
13
Device slave address selection pin (see the SMB Interface section for details). Checked only on
power-up or reset.
14
Digital output, open-drain, SMBALERT, active low. Requires a pull-up resistor (2.2 kΩ typical).
15
Bi-directional digital I/O pin, SMBus data, open-drain. Requires a pull-up resistor (2.2 kΩ typical).
16
Digital input, SMBus clock. Requires a pull-up resistor (2.2 kΩ typical).
Copyright © 2009, Texas Instruments Incorporated
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Product Folder Link(s): AMC6821-Q1