QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 566 DIGITALLY CONTROLLED PROGRAMMABLE GAIN AMPLIFIER LTC6910 DESCRIPTION Demonstration circuits 566A-A, -B and -C, feature the erate from single or split supplies from 2.7V to 10.5V easy to use, rail-to-rail input and output LTC6910 se- total between V+ and V-. ries of Low Noise Programmable Gain Amplifier Design files for this circuit board are available. Call (PGA) parts. The inverting gain is set by changing the the LTC factory. positions of three onboard jumpers: G0, G1 and G2 to set the 3-bit programming code. Demo Circuit 566A- Table 1. Performance Summary (T = 25C) A A is for the LTC69101 with gains of 0, 1, 2, 5, 10, PARAMETER CONDITION VALUE 20, 50, 100 V/V. Demo Circuit 566A-B is for the Supply Voltage Range V+ to V 2.7V to 10.5V LTC69102 with gains of 1, 2, 4, 8, 16, 32, and 64 Typical V/V. Demo Circuits 566A-C is for the LTC69103 with 0.05dB at gains of 1, 2, 3, 4, 5, 6 and 7 V/V. Gain Dependent (see Data Gain = 1 Gain Accuracy Sheet) All three-demo boards have input jumpers to select and 0.4 dB at Gain = 100 between AC or DC coupling of the input, and a jumper to select operation with a single or dual supply. Typi- Slew Rate Vs = 2.5V, V = 1.4V 12V/s OUT cal applications include data acquisition systems, dy- Vs = 5V, V = 1.4V 16V/s OUT namic gain changing, automatic ranging circuits and automatic gain control. The LTC6910 family can op- 50 50 20 V = 10V, V = 5mV V = 5V S IN RMS S GAIN OF 7 GAIN OF 6 V = 10mV IN RMS GAIN OF 100 (DIGITAL INPUT 111) 40 40 15 GAIN OF 64 GAIN OF 5 GAIN OF 32 GAIN OF 4 30 30 10 GAIN OF 50 (DIGITAL INPUT 110) GAIN OF 3 GAIN OF 16 GAIN OF 20 (DIGITAL INPUT 101) GAIN OF 8 20 20 5 GAIN OF 2 GAIN OF 10 (DIGITAL INPUT 100) GAIN OF 4 GAIN OF 1 GAIN OF 5 (DIGITAL INPUT 011) 10 10 0 GAIN OF 2 GAIN OF 2 (DIGITAL INPUT 010) GAIN OF 1 0 0 5 GAIN OF 1 (DIGITAL INPUT 001) V = 5V S V = 10mV IN RMS 10 10 10 100 1k 10k 100k 1M 10M 100 1k 10k 100k 1M 10M 100 1k 10k 100k 1M 10M FREQUENCY (Hz) FREQUENCY (Hz) FREQUENCY (Hz) 6910 G02 69102 TA02 69103 TA02 Figure 1. LTC6910-1 Frequency Re- Figure 2. LTC6910-2 Frequency Re- Figure 3. LTC6910-3 Frequency Re- sponse sponse sponse 1 GAIN (dB) GAIN (dB) GAIN (dB)QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 566 DIGITALLY CONTROLLED PROGRAMMABLE GAIN AMPLIFIER Figure 4. Proper Measurement Equipment Setup QUICK START PROCEDURE The 566 family of Demonstration boards allow for The jumper settings given in this procedure set the easy evaluation of the performance of the LTC6910 gain to a value of 1 (the LTC6910-X is an inverting series of PGAs. Refer to Figure 4 for proper meas- amplifier), for other gain values refer to Gain Table urement equipment setup and follow the procedure 2, 3 or 4 which matches the Demo Circuit, 566-A, - given below: B, or -C. To set the gain to a value of 1 set: 1. Place jumpers in the following positions: G0: Set to Logic 1 Supply Jumper: G1: Set to Logic 0 SINGLE for Single Supply G2: Set to Logic 0 DUAL for Dual Supply 2. With the power off, connect the input power supply to V+, V- and AGND as required. Input Jumper (IN): NOTE: Make sure that the input voltage does not DC for DC Coupling exceed 11V total between V+ and V. AC for AC Coupling 3. Set a function generator to output a 1kHz 1V PP f = 1/(2 C R ) 3dB 7 INPUT signal. C = 10F, R is the nominal input im- 7 INPUT 4. Set the input jumper to give the desired input cou- pedance and depends on the gain setting, pling, AC or DC. see Table 2, 3, or 4. 2