ASD5020L640INT Arctic Silicon Devices, ASD5020L640INT Datasheet - Page 17

• Manufacturer Part Number: ASD5020L640INT
• Description: ADC (A/D Converters) Mul-Md 12bit/640MSPS 8-bit 1000 MSPS ADC
• Manufacturer: Arctic Silicon Devices

Specifications of ASD5020L640INT

• Number Of Converters: 1
• Number Of Adc Inputs: 2
• Conversion Rate: 640 MSPs
• Resolution: 12 bit
• Snr: 70 dB
• Voltage Reference: 1 V
• Supply Voltage (max): 2 V
• Supply Voltage (min): 1.7 V
• Maximum Power Dissipation: 490 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-48
• Input Voltage: 1.8 V
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Preliminary Product Specification
Full-scale Control
The full-scale voltage range of ASD5020 can be adjusted using an internal 6-bit DAC controlled by the fs_cntrl register.
Changing the value in the register by one step, adjusts the full-scale range by approximately 0.3%. This leads to a
maximum range of ±10% adjustment. Table 9 shows how the register settings correspond to the full-scale range. Note
that the values for full-scale range adjustment are approximate. The DAC is, however, guaranteed to be monotonous.
The full-scale control and the programmable gain features differ in two major ways:
Current Control
There are two registers that impact performance and power dissipation.
The adc_curr register scales the current consumption in the ADC core. The performance is guaranteed at the nominal
setting. Lower power consumption can be achieved by reducing the adc_curr value, see table 10. The impact on
performance will depend on the ADC sampling rate.
ASD5020
fs_cntrl<5:0>
adc_curr<2:0>
ext_vcm_bc<1:0>
1.
2.
Name
Name
The full-scale control feature controls the full-scale voltage range in an analog fashion, whereas the
programmable gain is a digital feature.
The programmable gain feature has much coarser gain steps and larger range than the full-scale control.
Fine adjust ADC full scale range
ADC current scaling.
VCM buffer driving strength control.
Table 9: Register values with corresponding change in full-scale range
Description
Description
fs_cntrl<5:0>
adc_curr<2:0>
100001
100000
000001
000000
Table 10: ADC current control settings
111110
011111
111111
100
101
110
111
000 (default)
001
010
011
...
...
rev 2.0, 2010.11.08
0% change
Default
Default
Nominal
Nominal
Page 17 of 34
Full-scale range adjustment
-40%
-30%
-20%
-10%
Nominal
Do not use
Do not use
Do not use
ADC core current
D15 D14D13D12D11D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
D15 D14D13D12D11D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
+9.7%
+9.4%
+0.3%
−0.3%
−9.7%
−10%
+0%
...
...
X X X X X X
X X
High Speed Mode
X X X
Address
Address
0x55
0x50
Hex
Hex