emc2104 Standard Microsystems Corp., emc2104 Datasheet - Page 37

• Manufacturer Part Number: emc2104
• Description: Emc2104 Dual Rpm-based Pwm Fan Controller With Hardware Thermal Shutdown
• Manufacturer: Standard Microsystems Corp.

Dual RPM-Based PWM Fan Controller with Hardware Thermal Shutdown
Datasheet
SMSC EMC2104
5.13.1
5.14
5.15
i.e. CPU substrate PNP
substrate transistor
Typical remote
Local Ground
Diode Faults
The EMC2104 actively detects an open and short condition on each measurement channel. When a
diode fault is detected, the temperature data MSByte is forced to a value of 80h and the FAULT bit is
set in the Status Register. When the External Diode 3 channel is configured to operate in APD mode,
the circuitry will detect independent open fault conditions, however a short condition will be shared
between the External Diode 3 and External Diode 4 channels.
The EMC2104 contains up to three (3) GPIOs pin (all are multiplexed with other functions). The GPIO
pins can be configured as an input or an output and as a push-pull or open-drain output. Additionally,
the GPIO pins, when configured as an input, can be enabled to trigger an interrupt when they change
states.
If a change of state occurs (such as a temperature out-of-limit condition or a GPIO changing states)
then the following will occur:
1. The appropriate status bits will be set in the Status Register and in the High, Low, and Fault Status
2. The ALERT# will be asserted if the specific channel interrupt is enabled (see
The ALERT# pin is cleared by setting the MASK bit, disabling the specific interrupt channel enable, or
reading the status registers. If the error conditions persist, then the status bits will remain set. Unless
the Interrupt Status Enable bits are cleared or the MASK bit is set, the ALERT# pin will likewise be set.
GPIOs
Interrupts
Registers.
discrete PNP transistor
DP
DN
to
to
Typical remote
i.e. 2N3906
Figure 5.7 Diode Connections
DATASHEET
DN
DP
to
to
37
discrete NPN transistor
Typical remote
i.e. 2N3904
DP
DN
to
to
Anti-parallel diodes using
discrete NPN transistors
Diode 2
Revision 1.74 (05-08-08)
Section
Diode 1
6.15).