Document
RT9403A/B/C
I2C Programmable High Precision Reference Voltage Generator
General Description
Features
The RT9403A/B/C is a high precision reference voltage generating console consisting of three I2C programmable DACs. Each DAC output voltage is controlled by 7 digital bits that are programmed by the I2C interface. The RT9403A/B/C features adjustable output slew rate, low switching glitch and adequate driving capability. The RT9403A/B/C is available in SOT-23-8 package.
Ordering Information
RT9403A/B/C Package Type V8 : SOT-23-8
z 5V Supply Voltage z Provide 3 Precise Voltage DACs z I2C Programmable 128-Steps Output Voltage z Output Range and Resolution
` DAC1 & DAC2 : 0.6V to 2.1875V, 12.5mV/Step ` DAC3 : 1.2V to 3.375V, 12.5mV (or 25mV)/Step for Different Segments z High Output Accuracy Up to 1% (VOUT ≥ 1V) z Low External Component Count z Small Footprint SOT-23-8 Package z RoHS Compliant and Halogen Free
Lead Plating System
Applications
G : Green (Halogen Free and Pb Free)
z Power Supply Adjustment for Motherboard and Graphic
Address Bit [A1,A0]
A : [0,1]
Card
B : [1,0]
z Low Voltage, High Accuracy Reference Voltage Circuit
C : [1,1]
Note : Richtek products are :
Pin Configurations
(TOP VIEW)
S3/EN VOUT3 VOUT2 VOUT1
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
87 6 5
VDD GND SCL SDA
Marking Information
RT9403AGV8
01=DNN
01= : Product Code DNN : Date Code
2 34
SOT-23-8
RT9403BGV8 02=DNN
02= : Product Code DNN : Date Code
RT9403CGV8 04=DNN
04= : Product Code DNN : Date Code
DS9403A/B/C-00 May 2011
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RT9403A/B/C
Typical Application Circuit
Data Bus Line Clock Bus Line
3.3V/5V 5V
RT9403A/B/C
1 VDD CIN
S3/EN
4 SDA 3 SCL 8 S3/EN
VOUT1 5 VOUT2 6 VOUT3 7
GND 2
VIN1
REFIN DC/DC
COUT1
Converter
VIN2
REFIN DC/DC
COUT2
Converter
VIN3
REFIN DC/DC
COUT3
Converter
V1 V2 V3
Functional Pin Description
Pin No. Pin Name
Pin Function
1 VDD
Power Supply Input. Default connected to 5V.
2 GND 3 SCL 4 SDA 5 VOUT1 6 VOUT2 7 VOUT3
G round . Serial Clock Input. This pin receives I2C serial bus clock signal. Serial Data Input. This pin is input or output of I2C serial bus data signal. I2C Programmed VTT Output Voltage. Default = 1.1V I2C Programmed PCH_CORE Output Voltage. Default = 1.05V I2C Programmed DDR Output Voltage. Default = 1.5V
8 S3/EN
ACPI S3 State/Enable. Active low for entering ACPI S3 State(suspend to RAM), VOUT1/VOUT2 are internally pulled down to zero, only VOUT3 is active.
Function Block Diagram
VDD
I2C Interface
S3/EN SCL SDA
GND
POR
Control and Monitoring Unit
DAC1 7 bit
DAC2 7 bit
DAC3 7 bit
VOUT1 VOUT2 VOUT3
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DS9403A/B/C-00 May 2011
SVID6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
SVID5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
RT9403A/B/C
SVID4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0
Table 1. DAC1/DAC2 Serial Code Table
SVID3
S VID 2
SVID1
SVI D0
00 0 0
00 0 1
00 1 0
00 1 1
01 0 0
01 0 1
01 1 0
01 1 1
10 0 0
10 0 1
10 1 0
10 1 1
11 0 0
11 0 1
11 1 0
11 1 1
00 0 0
00 0 1
00 1 0
00 1 1
01 0 0
01 0 1
01 1 0
01 1 1
10 0 0
10 0 1
10 1 0
10 1 1
11 0 0
11 0 1
11 1 0
11 1 1
00 0 0
00 0 1
00 1 0
00 1 1
01 0 0
01 0 1
01 1 0
01 1 1
Output Voltage ( V ) 2.1 875 2.1 750 2.1 625 2.1 500 2.1 375 2.1 250 2 .112 5 2.1 000 2.0 875 2.0 750 2.0 625 2.0 500 2.0 375 2.0 250 2.0 125 2.0 000 1.9 875 1.9 750 1.9 625 1.9 500 1.9 375 1.9 250 1.9 125 1.9 000 1.8 875 1.8 750 1.8 625 1.8 500 1.8 375 1.8 250 1.8 125 1.8 000 1.7 875 1.7 750 1.7 625 1.7 500 1.7 375 1.7 250 1.7 125 1.7 000
To be continued
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RT9403A/B/C
S VI D6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
SVID5 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
SVID4 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Table 1. DAC1/DAC2 Serial Code Table
SVI D3
S VI D2
S VID 1
SVID0
1 00 0
1 00 1
1 01 0
1 01 1
1 10 0
1 10 1
1 11 0
1 11 1
0 00 0
0 00 1
0 01 0
0 01 1
0 10 0
0 10 1
0 11 0
0 11 1
1 00 0
1 00 1
1 01 0
1 01 1
1 10 0
1 10 1
1 11 0
1 11 1
0 00 0
0 00 1
0 01 0
0 01 1
0 10 0
0 10 1
0 11 0
0 11 1
1 00 0
1 00 1
1 01 0
1 01 1
1 10 0
1 10 1
1 11 0
1 11 1
Output Voltage ( V ) 1.68 75 1.67 50 1.66 25 1.6 500 1.63 75 1.62 50 1.61 25 1.60 00 1.58 75 1.57 50 1.56 25 1.55 00 1.53 75 1.52 50 1.51 25 1.50 00 1.48 75 1.47 50 1.46 25 1.45 00 1.43 75 1.42 50 1.41 25 1.40 00 1.38 75 1.37 50 1.36 25 1.35 00 1.33 75 1.32 50 1.31 25 1.30 00 1.28 75 1.27 50 1.26 25 1.25 00 1.23 75 1.22 50 1.21 25 1.20 00
To be continued
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DS9403A/B/C-00 May 2011
SVID6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1.