MAX187BCWE+ Maxim Integrated Products, MAX187BCWE+ Datasheet - Page 7

• Manufacturer Part Number: MAX187BCWE+
• Description: IC ADC SRL12BIT 5V 75KSPS 16SOIC
• Manufacturer: Maxim Integrated Products

Specifications of MAX187BCWE+

• Number Of Bits: 12
• Sampling Rate (per Second): 75k
• Data Interface: MICROWIRE™, QSPI™, Serial, SPI™
• Number Of Converters: 1
• Power Dissipation (max): 478mW
• Voltage Supply Source: Single Supply
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (0.300", 7.50mm Width)
• Number Of Adc Inputs: 1
• Architecture: SAR
• Conversion Rate: 75 KSPs
• Resolution: 12 bit
• Input Type: Voltage
• Interface Type: Serial
• Voltage Reference: Internal 4.096 V
• Supply Voltage (max): 5 V
• Maximum Power Dissipation: 478 mW
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX187/MAX189 use input track/hold (T/H) and
successive approximation register (SAR) circuitry to
convert an analog input signal to a digital 12-bit output.
No external hold capacitor is needed for the T/H.
Figures 3a and 3b show the MAX187/MAX189 in their
simplest configuration. The MAX187/MAX189 convert
input signals in the 0V to V
T/H acquisition time. The MAX187’s internal reference
is trimmed to 4.096V, while the MAX189 requires an
external reference. Both devices accept external refer-
ence voltages from +2.5V to V
requires only three digital lines, SCLK, CS, and DOUT,
and provides easy interface to microprocessors ( Ps).
Both converters have two modes: normal and shut-
down. Pulling SHDN low shuts the device down and
reduces supply current to below 10µA, while pulling
SHDN high or leaving it floating puts the device into the
operational mode. A conversion is initiated by CS
falling. The conversion result is available at DOUT in
_______________Detailed Description
_______________________________________________________________________Pin Description
DIP
—
—
—
1
2
3
4
5
6
7
8
PIN
2,4,5,7,9,13,14
WIDE SO
10
11
12
15
16
_______________________________________________________________________________________
—
1
3
6
8
REF
Converter Operation
+5V, Low-Power, 12-Bit Serial ADCs
NAME
DGND
range in 10µs, including
SHDN
AGND
DOUT
SCLK
DD
GND
N.C.
REF
V
AIN
CS
DD
. The serial interface
Three-level shutdown input. Pulling SHDN low shuts the MAX187/MAX189
down to 10µA (max) supply current. Both MAX187 and MAX189 are fully opera-
tional with either SHDN high or floating. For the MAX187, pulling SHDN high
enables the internal reference, and letting SHDN float disables the internal
reference and allows for the use of an external reference.
Reference voltage—sets analog voltage range and functions as a 4.096V output
for the MAX187 with enabled internal reference. REF also serves as a +2.5V to
V
and MAX189. Bypass with 4.7µF if internal reference is used, and with 0.1µF if an
external reference is applied.
Active-low chip select initiates conversions on the falling edge. When CS is high,
DOUT is high impedance.
Not internally connected. Connect to AGND for best noise performance.
Supply voltage, +5V ±5%
Sampling analog input, 0V to V
Analog and digital ground
Analog ground
Digital ground
Serial data output. Data changes state at SCLK’s falling edge.
Serial clock input. Clocks data out with rates up to 5MHz.
DD
input for a precision reference for both MAX187 (disabled internal reference)
unipolar serial format. A high bit, signaling the end of
conversion (EOC), followed by the data bits (MSB first),
make up the serial data stream.
The MAX187 operates in one of two states: (1) internal
reference and (2) external reference. Select internal
reference operation by forcing SHDN high, and external
reference operation by floating SHDN.
Figure 4 illustrates the sampling architecture of the
ADC’s analog comparator. The full-scale input voltage
depends on the voltage at REF.
For specified accuracy, the external reference voltage
range spans from +2.5V to V
Internal Reference
(MAX187 only)
External Reference
REFERENCE
FUNCTION
REF
range
ZERO
SCALE
0V
0V
DD
.
Analog Input
FULL
SCALE
+4.096V
V
REF
7