MAX1086ETA+T Maxim Integrated Products, MAX1086ETA+T Datasheet - Page 7

• Manufacturer Part Number: MAX1086ETA+T
• Description: IC ADC 10BIT 150KSPS 8-TDFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX1086ETA+T

• Number Of Bits: 10
• Sampling Rate (per Second): 150k
• Data Interface: MICROWIRE™, QSPI™, Serial, SPI™
• Number Of Converters: 1
• Power Dissipation (max): 1.6mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-WDFN Exposed Pad
• Number Of Adc Inputs: 2
• Architecture: SAR
• Conversion Rate: 150 KSPs
• Resolution: 10 bit
• Input Type: Differential
• Interface Type: 3-Wire (SPI, QSPI, MICROWIRE)
• Voltage Reference: External
• Supply Voltage (max): 5 V
• Maximum Power Dissipation: 1454.5 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: MAX1086ETA+T

The MAX1086–MAX1089 analog-to-digital converters
(ADCs) use a successive-approximation conversion (SAR)
technique and an on-chip track-and-hold (T/H) structure to
convert an analog signal into a 10-bit digital result.
Figure 3. Simplified Functional Diagram
1-Channel True-Differential ADCs in SOT23 and TDFN
PIN
—
1
2
3
4
5
6
7
8
CNVST
(AIN+)
(AIN-)
SCLK
AIN1
AIN2
REF
MAX1086
MAX1087
CNVST
DOUT
SCLK
( ) ARE FOR MAX1088/MAX1089
AIN1
AIN2
GND
V
REF
EP
MAX1086–MAX1089
DD
INPUT SHIFT
REGISTER
NAME
150ksps, 10-Bit, 2-Channel Single-Ended, and
_______________________________________________________________________________________
T/H
MAX1088
MAX1089
CNVST
DOUT
Detailed Description
SCLK
AIN+
GND
AIN-
V
REF
—
DD
OSCILLATOR
CONTROL
10-BIT
ADC
SAR
Positive Supply Voltage. +2.7V to +3.6V (MAX1087/MAX1089); +4.75V to +5.25V
(MAX1086/MAX1088). Bypass with a 0.1µF capacitor to GND.
Analog Input Channel 1 (MAX1086/MAX1087) or Positive Analog Input (MAX1088/MAX1089)
Analog Input Channel 2 (MAX1086/MAX1087) or Negative Analog Input (MAX1088/MAX1089)
Ground
External Reference Voltage Input. Sets the analog voltage range. Bypass with a 0.1µF
capacitor to GND.
Conversion Start. A rising edge powers-up the IC and places it in track mode. At the falling
edge of CNVST, the device enters hold mode and begins conversion. CNVST also selects the
input channel (MAX1086/MAX1087) or input polarity (MAX1088/MAX1089).
Serial Data Output. DOUT transitions the falling edge of SCLK. DOUT goes low at the start of a
conversion and presents the MSB at the completion of a conversion. DOUT goes high-
impedance once data has been fully clocked out.
Serial Clock Input. Clocks out data at DOUT MSB first.
Exposed Pad (TDFN only). Connect the exposed pad to ground or leave unconnected.
DOUT
The serial interface provides easy interfacing to micro-
processors (µPs). Figure 3 shows the simplified internal
structure for the MAX1086/MAX1087 (2–channels, sin-
gle-ended) and the MAX1088/MAX1089 (1–channel,
true-differential).
The equivalent circuit of Figure 4 shows the
MAX1086–MAX1089’s input architecture which is com-
posed of a T/H, input multiplexer, comparator, and
switched-capacitor DAC. The T/H enters its tracking
mode on the rising edge of CNVST. The positive input
capacitor is connected to AIN1 or AIN2 (MAX1086/
MAX1087) or AIN+ (MAX1088/MAX1089). The negative
input capacitor is connected to GND (MAX1086/
MAX1087) or AIN- (MAX1088/MAX1089). The T/H enters
its hold mode on the falling edge of CNVST and the dif-
ference between the sampled positive and negative
input voltages is converted. The time required for the T/H
to acquire an input signal is determined by how quickly
its input capacitance is charged. If the input signal’s
source impedance is high, the acquisition time length-
ens, and CNVST must be held high for a longer period of
time. The acquisition time, t
needed for the signal to be acquired, plus the power-up
time. It is calculated by the following equation:
True-Differential Analog Input Track/Hold
FUNCTION
t
ACQ
= 7 x (R
S
+ R
IN
ACQ
) x 24pF + t
Pin Description
, is the maximum time
PWR
7