1) Solder the 10-pin SIP resistor, provided with the kit,

in the R9 location on the EV kit board. The SIP resis-

tors act as pull-ups for the digital signals connected

to the 8-pin header. The marked end of R9 is pin 1.

2) Connect +5V and ground (GND) to the appropriate-

ly labeled pads on the evaluation board.

3) To operate the MAX186 in single-supply mode,

ground the header pin marked VSEL. Leaving the

ply operation).

4) Connect a clock signal (0.1MHz to 0.4MHz*) to the

header pin, labeled SCLK.

6) Connect an analog input source to the channel 7

input pad, labeled CH7.

7) Connect an oscilloscope, as shown in Figure 5 of

the MAX186/MAX188 data sheet.

*

To run at clock frequencies up to 2MHz, an external

compensation capacitor must be connected to the

VREF pin. Install the 22µF capacitor supplied with the

kit in location C6, and cut the trace across jumper

JU2 to disable the MAX186 internal compensation.

Detailed Description

An ICL7660 +5V to -5V converter and a DG413 analog

switch (mounted on the MAX186 evaluation board) pro-

between ground and -5V. The analog switch is not

voltage will be fixed at either -5V or ground. A negative

expected to go below ground.

The ICL7660 provides a -5V source with minimal addi-

tional circuitry. The ICL7660 converter circuit on the

MAX186 EV kit is the standard circuit for +5V to -5V

conversion. Its 10mA output capacity is much more

than is needed by the MAX186, which requires only

50µA. The additional current is available for user cir-

cuits in the prototyping area. For applications where

the MAX186 is the only load, the 10µF capacitors may

be reduced to 0.1µF.

MAX186 Evaluation System/Evaluation Kit

_______________________________________________________________________________________

3

Serial Interface

The 80C32 and MAX186 communicate through the 8

bits of port 1 on the 80C32. Table 1 lists the function of

each bit. The 80C32 drives MAX186 input data on the

DIN bit and receives data from the MAX186 on the

DOUT bit. For the first eight clock cycles after chip-

MAX186 on the rising edge of the serial clock (SCLK)

signal. For the 12 data-output clock cycles, the

MAX186 updates DOUT data on the falling edge of

SCLK. See the MAX186 data sheet for complete infor-

mation concerning the serial interface; Figures 6-12 of

the MAX186/MAX188 data sheet are timing diagrams

for operating in the internal and external clock modes.

Note that the maximum conversion rate of the EV sys-

tem is limited to 5ksps, because of the speed limitation

of the 80C32. For evaluation at full speed, see the

MAX186 EV Kit Quick Start section.

Table 1. Port 1 Bit Functions

MAX186 DIN pin. Transfers data from

the 80C32 to the MAX186.

DIN

P1.7

P1.6

CS

MAX186 CS pin. Enables serial com-

munications with the MAX186.

MAX186 DOUT pin. Transfers conver-

sion data from the MAX186 to the

80C32.

DOUT

P1.5

P1.4

SSTRB

MAX186 SSTRB pin. Provides the busy

output during internal clock mode (see

MAX186/MAX188 data sheet).

Not used

–

P1.3

P1.2

SHDN

Drives the MAX186 SHDN pin. Cut

jumper JU2 to float the SHDN pin.

Serial clock for data transfer

SCLK

P1.1

P1.0

pin between ground and -5V. Logic low,

FUNCTION

NAME

BIT