Evaluates: MAX117/MAX118 19-1104 Rev 0 7/96 MAX117 Evaluation Kit General Description Features The MAX117 evaluation kit (EV kit) is a fully assembled +3V (MAX117) or +5V (MAX118) Operation evaluation board for the 8-bit, 8-channel, +3V MAX117 analog-to-digital converter. Channel selection can be Fully Assembled and Tested controlled by switches located on the board or by user- On-Board Oscillator Generates Timing Signals provided logic-level signals. An on-board oscillator provides continuous conversions, and the conversion LED Display of Conversion Results results appear on the LED output display. Low-Power Shutdown Mode The MAX117 EV kit also evaluates the +5V MAX118. To evaluate the MAX118, order a MAX118 free sample, replace the MAX117 with the MAX118, and install the appropriate R9 resistor (see Component List). Component List Ordering Information DESIGNATION QTY DESCRIPTION PART TEMP. RANGE BOARD TYPE C1, C4 2 22F, 10V electrolytic capacitors MAX117EVKIT-DIP 0C to +70C Through Hole C2, C5C8 5 0.1F, 50V ceramic capacitors Note: To evaluate the MAX118, request a MAX118CPI free sample. C3 1 1000pF, 50V ceramic capacitor J1 1 20-pin ribbon-cable connector JU1, JU4 2 3-pin jumper headers JU2, JU3, 6 2-pin jumper headers JU5JU8 Quick Start LED1LED8 8 Red LEDs Verify operation of the MAX117 evaluation board by Low-R , N-channel FET DS(ON) N1 1 configuring for continuous conversions using the on- International Rectifier IRML2402* board oscillator. Take the following steps: R1, R2, R3, 5 100k resistors 1) Verify that the jumpers are configured as shown in R5, R6 Table 1. R4, R7, R8 3 10k resistors 2) Connect a +3V, 100mA supply to the VDD pad. A 330, 10-pin SIP resistor 20mA supply is sufficient if the LED output display (installed, used with MAX117) is disabled. To evaluate the MAX118, use a +5V R9 1 560, 10-pin SIP resistor supply and replace the 330, 10-pin SIP resistor (not installed, used with MAX118) (R9) with the 560 SIP resistor included in the kit. R10 1 5.1k resistor 3) Connect an input signal to the AIN1 input pad. SW1 1 4-position DIP switch 4) On switch SW1, set A0, A1, and A2 to the on posi- tion and set PD to the off position (Table 3). U1 1 MAX117CPI 5) Observe the conversion results on the LED display U2 1 74HC564 inverting 8-bit latch as the input voltage is varied between ground and U3 1 74HC04 hex inverter the supply voltage. None 8 Shunts None 1 Printed circuit board None 4 Rubber feet *International Rectifier: (310) 322-3331 Maxim Integrated Products 1 For free samples & the latest literature: MAX117 Evaluation Kit Shutdown Table 1. Jumper Configuration for When switch PD is set to the on position, the MAX117 Continuous-Conversion Operation enters shutdown mode. In shutdown mode, the supply current drops below 1A (excluding the reference cur- JUMPER CONNECTION FUNCTION rent). The internal resistance from REF+ to REF- is typi- Connects REF- to the drain cally 2k, and current will flow through it even when the JU1 1 & 2 of N1 (see the Shutdown MAX117 is shut down. The evaluation kit uses a low- section). RDS(ON), N-channel MOSFET (N1) to disconnect REF- from ground when the MAX117s PWRDN pin is driven Sets the MAX117 for READ JU2 Open low. This MOSFET has less than 1 of on-resistance at mode operation (MODE = low). 2.7V VGS to prevent an excessive offset error from JU3 Shorted Enables the LED display. appearing at REF-. Jumper JU1 allows the user to Connects the CS pin to the remove N1 from the circuit to evaluate user-specific cir- JU4 2 & 3 on-board oscillator. cuit configurations. Connects the MAX117s V DD Current Measurement JU5 Shorted pin to the on-board EV kits The current supplied to the board includes the current VDD pad. drawn by the MAX117, the on-board oscillator, the out- put latch, and the LED display. Jumper JU5 is in series Connects the RD pin to the JU6 Shorted on-board oscillator. with the MAX117 V pin to facilitate MAX117 supply- DD current measurements. Measure the MAX117 supply Connects the MAX117s REF+ JU7 Shorted current or shutdown current by removing the shunt that pin to VDD. normally shorts JU5, and connecting an ammeter Connects a pull-up resistor to across the two jumper pins. Refer to Table 2 for the JU8 Shorted the WR/RDY pin. appropriate jumper/switch settings. Table 2. Jumper/Switch Settings for Detailed Description MAX117 Current Measurements MAX117 Reference Voltage The MAX117 reference can be connected to any volt- JUMPERS SWITCH CURRENT age between V and ground (V + V -). To use DD REF REF MEASUREMENT JU1 JU7 the power-supply rails as the reference voltage, short Supply Current, jumper JU7 and install a shunt on JU1 (in either posi- 2 & 3 or V = V (including Shorted Off REF DD tion). When using an external reference, remove the 1 & 2 reference current) shunts from JU1 and JU7, and apply your external ref- erence source to the VREF+ and VREF- pads. Supply Current (excluding Open Open Off reference current Continuous Conversions Power-Down Current 1 & 2 N/A On A 74HC04, configured as a free-running oscillator, pro- vides the continuous-conversion signals (CS and RD) on the evaluation board. The oscillator output also clocks the MAX117 conversion results into a 74HC564 octal latch for display by eight LEDs. The oscillator must be disconnected when the MAX117 is controlled by external circuitry. Remove the shunts from jumpers JU4, JU6, and JU8 to disconnect the on-board oscillator. For additional flexibility, the digital signals and data outputs are available at the 20-pin connector, J1. 2 Evaluates: MAX117/MAX118 PD