JAJSLI5J January 2011 – March 2021 OPA2835 , OPA835
PRODUCTION DATA
The OPA835 RUN package option includes integrated gain-setting resistors for the smallest possible footprint on a printed circuit board (≈ 2.00 mm x 2.00 mm). By adding circuit traces on the PCB, gains of +1, –1, –1.33, +2, +2.33, -3, +4, –4, +5, –5.33, +6.33, –7, +8 and inverting attenuations of –0.1429, –0.1875, –0.25, –0.33, –0.75 can be achieved.
Figure 9-6 shows a simplified view of how the OPA835IRUN integrated gain-setting network is implemented. Table 9-1 lists the required pin connections for various noninverting and inverting gains (reference Figure 8-1 and Figure 8-2). Table 9-2 lists the required pin connections for various attenuations using the inverting-amplifier architecture (reference Figure 8-2). Due to ESD protection devices being used on all pins, the absolute maximum and minimum input voltage range, VS– – 0.7 V to VS+ + 0.7 V, applies to the gain-setting resistors, and so attenuation of large input voltages will require external resistors to implement.
The gain-setting resistors are laser trimmed to 1% tolerance with nominal values of 2.4 kΩ, 1.8 kΩ, and 600 Ω. The gain-setting resistors have excellent temperature coefficient, and gain tracking is superior to using external gain-setting resistors. The 800-Ω resistor and 1.25-pF capacitor in parallel with the 2.4-kΩ gain-setting resistor provide compensation for best stability and pulse response.
NONINVERTING
GAIN (Figure 8-1) |
INVERTING
GAIN (Figure 8-2) |
SHORT PINS | SHORT PINS | SHORT PINS | SHORT PINS |
---|---|---|---|---|---|
1 V/V (0 dB) | — | 1 to 9 | — | ||
2 V/V (6.02 dB) | –1 V/V (0 dB) | 1 to 9 | 2 to 8 | 6 to GND | — |
2.33 V/V (7.36 dB) | –1.33 V/V (2.5 dB) | 1 to 9 | 2 to 8 | 7 to GND | — |
4 V/V (12.04 dB) | –3 V/V (9.54 dB) | 1 to 8 | 2 to 7 | 6 to GND | — |
5 V/V (13.98 dB) | –4 V/V (12.04 dB) | 1 to 9 | 2 to 7 or 8 | 7 to 8 | 6 to GND |
6.33 V/V (16.03 dB) | –5.33 V/V (14.54 dB) | 1 to 9 | 2 to 6 or 8 | 6 to 8 | 7 to GND |
8 V/V (18.06 dB) | –7 V/V (16.90 dB) | 1 to 9 | 2 to 7 | 6 to GND | — |
INVERTING
GAIN (Figure 8-2) |
SHORT PINS | SHORT PINS | SHORT PINS | SHORT PINS |
---|---|---|---|---|
–0.75 V/V (–2.5 dB) | 1 to 7 | 2 to 8 | 9 to GND | — |
–0.333 V/V (–9.54 dB) | 1 to 6 | 2 to 7 | 8 to GND | — |
–0.25 V/V (–12.04 dB) | 1 to 6 | 2 to 7 or 8 | 7 to 8 | 9 to GND |
–0.1875 V/V (–14.54 dB) | 1 to 7 | 2 to 6 or 8 | 6 to 8 | 9 to GND |
–0.1429 V/V (–16.90 dB) | 1 to 6 | 2 to 7 | 9 to GND | — |