SNAS648C October 2014 – February 2023 TDC1000
PRODUCTION DATA
The PGA, shown in #SNAS6489907, is an inverting amplifier with an input resistance of RIN = 500 Ω and a programmable feedback resistor RFB that can be programmed to set a 0-dB to 21-dB gain in 3-dB steps. This can be done by programming the PGA_GAIN field in the TOF_1 register. The bandwidth of the PGA is scaled based on the programmed gain. Table 8-1 lists the typical bandwidth of the PGA with a 100-kΩ load to VCM and a 10-pF capacitor to ground.
PGA_GAIN (HEX) | GAIN (dB) | BANDWIDTH (MHz) |
---|---|---|
0h | 0 | 19.0 |
1h | 3 | 16.8 |
2h | 6 | 14.4 |
3h | 9 | 12.3 |
4h | 12 | 10.0 |
5h | 15 | 8.2 |
6h | 18 | 6.6 |
7h | 21 | 5.0 |
The PGA can be bypassed and disabled by writing a 1 to the PGA_CTRL bit in the TOF_1 register. The output of the PGA should not be loaded directly with capacitances greater than 10 pF.