SBOU024C august 2004 – july 2023 PGA309
Bit # | D15 | D14 | D13 | D12 | D11 | D10 | D9 | D8 | D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 |
Bit Name | GD15 | GD14 | GD13 | GD12 | GD11 | GD10 | GD9 | GD8 | GD7 | GD6 | GD5 | GD4 | GD3 | GD2 | GD1 | GD0 |
POR Value | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Bit Descriptions:
GD[15:0]: Gain DAC control, 16-bit unsigned data format
Digital Input (Hex) | Digital Input ZD15............ZD0 (Binary) | Gain Adjust |
---|---|---|
0000 | 0000 0000 0000 0000 | 0.333333333 |
0001 | 0000 0000 0000 0001 | 0.333343505 |
32F2 | 0011 0010 1111 0010 | 0.466003417 |
4000 | 0100 0000 0000 0000 | 0.500000000 |
6604 | 0110 0110 0000 0100 | 0.598999023 |
9979 | 1001 1001 0111 1001 | 0.733001708 |
CC86 | 1100 1100 1000 0110 | 0.865997314 |
FFFF | 1111 1111 1111 1111 | 1.000000000 |
Gain DAC Equation:
1 LSB = (1.000000000 – 0.333333333) / 65536 = (2/3)/65536
Decimal # Counts = (Desired Gain – 1/3)/(3/2)(65.536)
0.3333333 ≤ Gain DAC ≤ 0.9999898
0 ≤ Gain DAC Counts ≤ 65535
Gain DAC Example:
Want: Fine Gain = 0.68
Decimal # Counts = (0.68 − 1/3)(3/2)(65536) = 34078.72
Use 34079 counts → 851Fh → 1000 0101 0001 1111