Click here to ask about the production status of specific part numbers. Evaluates: MAX40108 MAX40108 Evaluation Kit Procedure General Description The EV kit is fully assembled and tested. Follow the steps The MAX40108 evaluation kit (EV kit) provides a proven below to verify board operation: design to evaluate the MAX40108 precision, low-noise, low-drift dual-operational amplifier in a 6-bump wafer- 1) Verify that all jumpers (JU1JU3) are in their default level package (WLP). The EV kit circuit is preconfigured positions, as shown in Table 1. as noninverting amplifiers, but can be adapted to other 2) Set the power supply to 1.5V. Connect the positive topologies by changing a few components. terminal of the power supply to V and the negative CC The EV kit comes with a MAX40108ANT+ installed. terminal to GND and V . SS 3) Connect the positive terminal of the precision volt- Features age source to INP. Connect the negative terminal of Accommodates Multiple Op Amp Configurations the precision voltage source to GND. INM is already Component Pads Allow for Sallen-Key Filter connected to GND through jumper JU1. Accommodates Easy-to-Use Components 4) Connect the DMM to monitor the voltage on OUT. With the 10k feedback resistors and 1k series resistors, the Proven PCB Layout gain of the noninverting amplifier is +11V/V. Fully Assembled and Tested 5) Turn on the power supply. Quick Start 6) Apply 100mV from the precision voltage sources. Observe the output at OUT on the DMM that reads Required Equipment approximately +1.1V. MAX40108 EV kit Note: For dual-supply operation, a 0.45V to 1.8V sup- +0.9V to +3.6V, 20mA DC power supply (PS1) ply can be applied to V and V , respectively. The rest DD SS Precision voltage source of the procedure remains the same as that of the single- supply operation. Digital multimeter To shut down during dual-supply operation, connect JU3 (pin 2) to V . Do not use the JU3, 2-3 jumper placement. Ordering Information appears at end of data sheet. SS 319-100550 Rev 0 6/20Evaluates: MAX40108 MAX40108 Evaluation Kit as a unity-gain buffer by replacing R5 with a 0 resistor Detailed Description of Hardware and removing resistor R1. The signal is noninverting and The MAX40108 EV kit provides a proven layout for precision, applied to INP. The filter component pads are R2R7 and low-noise, low-drift op amp. The device is a single/dual- R8, where some have to be populated with resistors and supply op amp with rail-to-rail inputs and outputs, available others with capacitors. in 6-bump WLP (1.22mm x 0.92mm) space-saving package. Lowpass Sallen-Key Filter: To configure the Sallen-Key The default configuration for the device in the EV kit is as a lowpass filter, remove the shunt from jumper JU1, single-supply operation in a noninverting configuration. populate the R2 and R8 pads with resistors, and populate However, the device can operate with a dual supply as long the R3 and R7 pads with capacitors. The corner frequency as the voltage across the V and V pins of the IC do DD SS and Q are then given by: not exceed the absolute maximum ratings. When operating with a single supply, short V to GND. SS 1 f = C Op Amp Configurations 2R R C C R2 R8 R3 R7 The device is a single/dual-supply op amp that is ideal for differential sensing, noninverting amplification, buffering, RR C C R2 R8 R3 R7 and filtering. A few common op amp configurations are Q = C (R + R ) explained in the next few sections. R3 R2 R8 Noninverting Configuration Highpass Sallen-Key Filter: To configure the Sallen- The EV kit comes preconfigured as a noninverting amplifier. Key as a highpass filter, remove the shunt from jumper The gain is set by the ratio of R5 and R1. The EV kit JU1, populate the R3 and R7 pads with resistors, and comes preconfigured for a gain of +11V/V. The output populate the R2 and R8 pads with capacitors. The corner voltage for the noninverting configuration is given by the frequency and Q are then given by: equation below: 1 f = R5 C V =(1+ )V V 2R R C C OUTA INAP OS R3 R7 R2 R8 R1 Inverting Configuration R RC C R3 R7 R2 R8 To configure the EV kit as an inverting amplifier, remove Q = R (C + C ) the shunt on jumper JU1, install a shunt on jumper JU2, R7 R2 R8 and feed an input signal on the INM PCB pad. Bandpass Sallen-Key Filter: To configure the Sallen- Differential Amplifier Key as a bandpass filter, remove the shunt from jumper To configure the EV kit as a differential amplifier, replace JU1, replace R8, populate the R3 and R7 pads with resistors, R1R3 and R5 with appropriate resistors. When R1 = R2 and populate the C8 and R2 pads with capacitors. The and R3 = R5, the CMRR of the differential amplifier is corner frequency and Q are then given by: determined by the matching of the resistor ratios R1/R2 1 R + R and R3/R5. R7 R8 f = C 2 C C RRR C8 R2 R8 R3 R7 V = GAIN(V V ) OUTA INP INM where: R + R C C RRR ( ) R5 R3 R7 R8 C8 R2 R8 R3 R7 GAIN Q = R R1 R2 R5 R R C ++C R C (R R ) ( ) R7 R8 C8 R2 R3 R2 R7 R8 R R1 Sallen-Key Configuration The Sallen-Key topology is ideal for filtering sensor signals with a second-order filter and acting as a buffer. Schematic complexity is reduced by combining the filter and buffer operations. The EV kit can be configured in a Sallen-Key topology by replacing and populating a few components. The Sallen-Key topology can be configured Maxim Integrated 2 www.maximintegrated.com = =