MAX187EVKIT-DIP Maxim Integrated, MAX187EVKIT-DIP Datasheet - Page 7

• Manufacturer Part Number: MAX187EVKIT-DIP
• Description: Data Conversion IC Development Tools Programmers, Development Systems
• Manufacturer: Maxim Integrated
• Series: MAX187, MAX189r

Specifications of MAX187EVKIT-DIP

• Interface Type: QSPI, Serial (SPI, Microwire)
• Factory Pack Quantity: 1

To measure the amount of supply current drawn by the
MAX187, use the following procedure:
1) Turn off the power to the EV system.
2) Carefully cut the trace at J2.
3) Install a 2-pin header at J2.
4) Connect a current meter in series with J2.
The direction of current flow is marked with an arrow.
Do not connect or disconnect the current meter while
the power is on.
After observing supply current in operating and in shut-
down modes, the board may be restored by installing a
shunt at J2.
The 68HC16 and MAX187 communicate through the
QSPI port on the 40-pin data connector. Table 5 lists
the function of each bit when interfaced to the 68HC16
module. Figure 1b shows the QSPI interface schematic
diagram.
Table 5. Data-Interface Connections for
68HC16
All other pins are reserved.
PIN
No.
1–4
7–8
30
35
37
38
68HC16
SIGNAL
GND
+5V
OC1
MISO
SCK
PSC0
MAX187 Evaluation System/Evaluation Kit
MAX187
SIGNAL
AGND
+5V
SHDN
DOUT
SCLK
CS
_______________________________________________________________________________________
Measuring Supply Current
Data-Connector Interface
Ground
+5V Supply to MAX187
Evaluation Board
Shutdown Pin
Serial Data Output from
MAX187
Serial Clock from 68HC16
Chip Select from 68HC16
FUNCTION
A 68HC11 can use its SPI™ (serial peripheral inter-
face) to read a MAX187. Table 6 lists the interface
connections required by the SPI serial interface.
Figure 2 is a schematic diagram of the SPI interface.
Listing 2 shows how to use the SPI to read the
MAX187. The algorithm is as follows:
10) Extract the 12 significant bits from the 16 bits that
Table 6. 68HC11/SPI Interface
Connections
_______________________SPI Interface
™ SPI is a trademark of Motorola Corp.
1) Initialize SPI parameters:
2) Assert CS low.
3) Wait until MISO goes high.
4) Begin SPI transfer.
5) Wait until SPI transfer is complete.
6) Save the first 8 bits in temporary storage. This first
7) Continue the SPI transfer.
8) Wait until SPI transfer is complete.
9) Negate CS high.
SPARE I/O
OUTPUT
SIGNAL
SPARE
SPI byte contains the start bit followed by MAX187
data bits 11–5.
the SPI read. The second SPI byte contains
MAX187 data bits 4–0 followed by three zero bits.
MISO
SCK
SPI
SS
Master Mode
SPR = 00 (1MHz serial clock)
CPOL = 0, CPHA = 0
MAX187
SIGNAL
SHDN
DOUT
SCLK
CS
—
Shutdown Pin
Chip Select from 68HC11
Serial Data Output from MAX187
Serial Clock from 68HC11
Slave Select Input to 68HC11;
must be pulled up to 5V.
FUNCTION
7