HPFANG Datasheet, PDF (1/9 Pages) Champion Microelectronic Corp. – HP Power Supply Fan Controller DATA SHEET

http://www.championmicro.com.tw
General Description:
HPFANG+/-
HP Power Supply Fan Controller DATA SHEET
FEATURES
HPFANG+/- is designed for HP related application. The
target application is for the Fan Control Section of HP PC
Power Supply. It might infringe HP patent if the application
is not relate to HP related business.
HPFANG+/- is designed to achieve high performance and
high efficiency with low cost BOM. With HPFANG+/-, the
application may reduce one FAN. It combines PC
motherboard temperature information and the temperature
information of PC power supply. The temperature
information of PC power supply is an analog signal called
TFB, which can be generated by a simple Thermistor. The
temperature information of PC motherboard usually is
presented by the duty cycle of the signal called FANCMD.
TEAO and TFB are output and inverting input of the OP.
The non-inverting input of TEAO OP is connected to internal
2.5V reference. A simple inverting gain configuration with
a thermistor in series of a current limit resistor Rs can
program the TEAO to search for the duty cycle of
FANPWMOUT which corresponds with the fan speed at the
temperature. When TEAO is greater than 3.5V, the
FANPWMOUT duty cycle is 100%. When TEAO is ~ 2.5V,
the FANPWMOUT duty cycle is ~50%. When TEAO is
below 1.5V, the FANPWMOUT duty cycle is ~ 1.5%.
Usually, 50% duty cycle of FANPWMOUT corresponds to
50% Power Supply load at room temperature, and 5% duty
cycle of FANPWMOUT corresponds to 20% Power Supply
load at room temperature. To have FANPWMOUT ~ 50%,
TEAO is ~2.5V.
FANCMD is represented as motherboard temperature
information. FANCMD usually is a 25KHz PWMing signal.
The amplitude of FANCMD needs to be greater than 1.5V
and lower than 5V to work with HPFANG+/-.
HPFANG+/- is inverting the complimentary duty cycle of
FANCMD to FANPWMOUT. FANCMD duty cycle is ~
FANPWMOUT duty cycle.
HPFANG+/- selects the highest voltage among TEAO,
CAVERAGE to compare with oscillator ramp, which is 1.5V
to 3.5V.
HPFANG+/- design tool is available. Please contact
Champion Sales.
‹ Combine Mother Board Temperature Signals with Power
Supply Temperature Signals
‹ Low BOM and It may reduce one Fan
‹ Precision OP (TEAO) uses TFB to sense the thermistor
information at power supply
‹ Precision 25KHz Ramp generator: Peak ~ 3.5V (Duty
~100%) and Valley ~1.5V (Duty ~1.5%)
‹ Precision 25KHz Ramp generator compares TEAO,
Caverage, and Fault to determine the duty cycle of
FANPWMOUT
‹ It does not require negative voltage
‹ Accept Pulse PWMing signal FANCMD (prefer it is
below 100Khz) from Mother Board
‹ Precision Duty to Duty Converter or called a Pulse to
Pulse Converter or called PWMing to PWMing Converter
‹ The amplitude of Input pulse (FANCMD), peak to peak
can be from 0V - 5V to 0V - 2V
‹ Minimum VCC > 8V Power Supply
‹ Preferred VCC~ 12V
‹ Precision (1% variation) 5V Reference Voltage
‹ Precision Internally Generated 25KHz +/-10% Switching
Frequency
‹ FANPWMOUT 1.5% to 100% Output Duty Cycle
‹ Thermal Shut Down can be done by sensing TFB or
TEAO
‹ Low Operating Current, Ivcc ~ 0.5mA
‹ HPFANG+ : Input Signal FANCMD 25% Duty (+)
Output Signal FANCMD 25% Duty (+)
‹ HPFANG- : Input Signal FANCMD 25% Duty (-)
Output Signal FANCMD 75% Duty (-)
‹ 8 pin package : DIP & SOP Package
2013/01/17 Rev. 1.2
Champion Microelectronic Corporation
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