ADT7475ARQZ ON Semiconductor, ADT7475ARQZ Datasheet - Page 12

• Manufacturer Part Number: ADT7475ARQZ
• Description: IC REMOTE THERMAL CTRLR 16-QSOP
• Manufacturer: ON Semiconductor
• Series: dBCool®r

Specifications of ADT7475ARQZ

• Function: Fan Control, Temp Monitor
• Topology: ADC, Comparator, Fan Speed Counter, Multiplexer, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: -40°C ~ 125°C, External Sensor
• Output Type: SMBus™
• Output Alarm: No
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Full Temp Accuracy: +/- 0.5 C
• Digital Output - Bus Interface: Serial (3-Wire, 4-Wire)
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

This effectively gives a reading 16 times faster (711 ms), but
the reading may be noisier.
Bypass Voltage Input Attenuator
the attenuation circuitry from the V
the user to directly connect external sensors or to rescale the
analog voltage measurement inputs for other applications.
The input range of the ADC without the attenuators is 0 V
to 2.25 V.
Single−Channel ADC Conversion
ADT7475 into single−channel ADC conversion mode. In
this mode, the ADT7475 can be made to read a single
voltage channel only. If the internal ADT7475 clock is used,
the selected input is read every 711 ms. The appropriate ADC
channel is selected by writing to Bits [7:5] of the TACH1
minimum high byte register (0x55).
1. The V
Table 2. 10−Bit ADC Output Code vs. V
Setting Bit 5 of Configuration Register 2 (0x73) removes
Setting Bit 6 of Configuration Register 2 (0x73) places the
V
CC
CC
0.0042 to 0.0085
0.0085 to 0.0128
0.0128 to 0.0171
0.0171 to 0.0214
0.0214 to 0.0257
0.0257 to 0.0300
0.0300 to 0.0343
0.0343 to 0.0386
4.3527 to 4.3570
4.3570 to 4.3613
4.3613 to 4.3656
4.3656 to 4.3699
4.3699 to 4.3742
4.3742 to 4.3785
4.3785 to 4.3828
4.3828 to 4.3871
4.3871 to 4.3914
4.3914 to 4.3957
1.100 to 1.1042
2.200 to 2.2042
3.300 to 3.3042
(3.3 V
output codes listed assume that V
<0.0042
>4.3957
−
−
−
−
IN
) (Note 1)
CCP
0.0293 to 0.0058
0.0058 to 0.0087
0.0087 to 0.0117
0.0117 to 0.0146
0.0146 to 0.0175
0.0175 to 0.0205
0.0205 to 0.0234
0.0234 to 0.0263
0.7500 to 0.7529
1.5000 to 1.5029
2.2500 to 2.2529
2.9677 to 2.9707
2.9707 to 2.9736
2.9736 to 2.9765
2.9765 to 2.9794
2.9794 to 2.9824
2.9824 to 2.9853
2.9853 to 2.9882
2.9882 to 2.9912
2.9912 to 2.9941
2.9941 to 2.9970
input. This allows
CC
IN
<0.00293
>2.9970
is 3.3 V and that V
V
CCP
−
−
−
−
http://onsemi.com
ADC Output
CC
12
should never exceed 3.6 V.
Configuration Register 2 (0x73)
Bit 4 = 1; averaging off.
Bit 5 = 1; bypass input attenuators.
Bit 6 = 1; single−channel convert mode.
TACH1 Minimum High Byte (0x55)
Bits [7:5] select the ADC channel for single−channel
convert mode.
Table 1. Single−Channel ADC Conversion
Register 0x55, Bits [7:5]
256 (
512 (
768 (
Decimal
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1/4
1/2
3/4
001
010
101
110
111
0
1
2
3
4
5
6
7
8
−
−
−
−
scale)
scale)
scale)
V
V
Remote 1 Temperature
Local Temperature
Remote 2 Temperature
CCP
CC
Channel Selected
Binary (10 Bits)
00000000 00
00000000 01
00000000 10
00000001 00
00000001 01
00000001 10
00000010 00
01000000 00
10000000 00
00000000 11
00000001 11
11000000 00
11111101 01
11111101 10
11111101 11
11111110 00
11111110 01
11111110 10
11111110 11
11111111 00
11111111 01
11111111 10
11111111 11
−
−
−
−