Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsData collecting ICsData acquisition IC - AD converter (ADC) External , Internal uMAX 10

General Description

The MAX1108/MAX1109 low-power, 8-bit, dual-channel,

analog-to-digital converters (ADCs) feature an internal

track/hold (T/H) voltage reference, clock, and serial inter-

face. The MAX1108 is specified from +2.7V to +3.6V and

consumes only 105µA. The MAX1109 is specified from

+4.5V to +5.5V and consumes only 130µA. The analog

inputs are software configurable, allowing unipolar/bipolar

and single-ended/differential operation; battery monitor-

ing capability is also included.

The full-scale analog input range is determined by the

internal reference of +2.048V (MAX1108) or +4.096V

(MAX1109), or by an externally applied reference rang-

ing from 1V to V

. The MAX1108/MAX1109 also feature

a software power-down mode that reduces power con-

sumption to 0.5µA when the device is not in use. The

4-wire serial interface directly connects to SPI™, QSPI™,

and MICROWIRE™ devices without external logic.

Conversions up to 50ksps are performed using either the

internal clock or an external serial-interface clock.

The MAX1108 and MAX1109 are available in a 10-pin

µMAX package with a footprint that is just 20% of an

8-pin plastic DIP.

Applications

Portable Data Logging

Hand-Held Measurement Devices

Medical Instruments

System Diagnostics

Solar-Powered Remote Systems

4–20mA-Powered Remote Systems

Receive-Signal Strength Indicators

Features

♦ Single Supply: +2.7V to +3.6V (MAX1108)

+4.5V to +5.5V (MAX1109)

♦ Low Power: 105µA at +3V and 50ksps

0.5µA in Power-Down Mode

♦ Software-Configurable Unipolar or Bipolar Inputs

♦ Input Voltage Range: 0 to V

♦ Internal Track/Hold

♦ Internal Reference: +2.048V (MAX1108)

+4.096V (MAX1109)

♦ Reference Input Range: 1V to V

♦ SPI/QSPI/MICROWIRE-Compatible Serial Interface

♦ V

Monitoring Mode

♦ Small 10-Pin µMAX Package

MAX1108/MAX1109

Single-Supply, Low-Power,

2-Channel, Serial 8-Bit ADCs

________________________________________________________________ Maxim Integrated Products 1

SCLK

DOUT

DIN

CSGND

CH1

CH0

MAX1108

MAX1109

µMAX

TOP VIEW

COMREF

INPUT

SHIFT

CONTROL

LOGIC

T/H

SAR

INTERNAL

OSCILLATOR

OUTPUT

SHIFT

ANALOG

INPUT

MUX

INTERNAL

REFERENCE

DOUT

SCLK

DIN

CH0

COM

REF

CH1

GND

CHARGE

REDISTRIBUTION

DAC

MAX1108

MAX1109

Functional Diagram

19-1399; Rev 1; 6/03

Pin Configuration

Ordering Information

PART

MAX1108CUB

MAX1108EUB -40°C to +85°C

0°C to +70°C

TEMP RANGE PIN-PACKAGE

10 µMAX

MAX1109CUB

MAX1109EUB -40°C to +85°C

0°C to +70°C 10 µMAX

10 µMAX

SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp.

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Summary of content (20 pages)

PAGE 1
9-1399; Rev 1; 6/03 Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs Features The MAX1108/MAX1109 low-power, 8-bit, dual-channel, analog-to-digital converters (ADCs) feature an internal track/hold (T/H) voltage reference, clock, and serial interface. The MAX1108 is specified from +2.7V to +3.6V and consumes only 105µA. The MAX1109 is specified from +4.5V to +5.5V and consumes only 130µA.
PAGE 2
MAX1108/MAX1109 Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs ABSOLUTE MAXIMUM RATINGS VDD to GND ..............................................................-0.3V to +6V CH0, CH1, COM, REF, DOUT to GND .......-0.3V to (VDD + 0.3V) DIN, SCLK, CS to GND ............................................-0.3V to +6V Continuous Power Dissipation (TA = +70°C) 10-pin µMAX (derate 5.6mW/°C above +70°C) ............444mW Operating Temperature Ranges MAX110_CUB ...............................................
PAGE 3
Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs (VDD = +2.7V to +3.6V; unipolar input mode; COM = GND, fSCLK = 500kHz, external clock mode (50% duty cycle); 10 clocks/conversion cycle (50ksps); 1µF capacitor at REF, external +2.048V reference at REF; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25°C.
PAGE 4
MAX1108/MAX1109 Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs ELECTRICAL CHARACTERISTICS—MAX1108 (continued) (VDD = +2.7V to +3.6V; unipolar input mode; COM = GND, fSCLK = 500kHz, external clock mode (50% duty cycle); 10 clocks/conversion cycle (50ksps); 1µF capacitor at REF, external +2.048V reference at REF; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25°C.
PAGE 5
Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs (VDD = +4.5V to +5.5V; unipolar input mode; COM = GND, fSCLK = 500kHz, external clock (50% duty cycle); 10 clocks/conversion cycle (50ksps); 1µF capacitor at REF, external +4.096V reference at REF; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DYNAMIC PERFORMANCE (10kHz sine-wave input, 4.
PAGE 6
MAX1108/MAX1109 Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs ELECTRICAL CHARACTERISTICS—MAX1109 (continued) (VDD = +4.5V to +5.5V; unipolar input mode; COM = GND, fSCLK = 500kHz, external clock (50% duty cycle); 10 clocks/conversion cycle (50ksps); 1µF capacitor at REF, external +4.096V reference at REF; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 4.5 5 5.
PAGE 7
Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs (VDD = +4.5V to +5.5V; unipolar input mode; COM = GND, fSCLK = 500kHz, external clock (50% duty cycle); 10 clocks/conversion cycle (50ksps); 1µF capacitor at REF, external +4.096V reference at REF; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25°C.
PAGE 8
Typical Operating Characteristics (continued) (VDD = +3.0V (MAX1108), VDD = +5.0V (MAX1109); external conversion mode; fSCLK = 500kHz; 50ksps; external reference; 1µF at REF; TA = +25°C; unless otherwise noted.) OFFSET ERROR vs. TEMPERATURE 0.4 0.2 0.1 0 -0.1 -0.2 0.2 0.1 0 -0.1 -0.2 -0.3 -0.3 -0.4 -0.4 -0.5 -0.5 3.5 4.0 4.5 5.0 5.5 -0.05 -0.15 -0.20 -40 -20 0 20 40 60 80 100 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 TEMPERATURE (°C) GAIN ERROR vs. SUPPLY VOLTAGE 0.8 0.
PAGE 9
Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs FFT PLOT 0 -0.1 -20 -40 -60 -0.2 -0.3 INTERNAL CONVERSION MODE 20.5 CONVERSION TIME(µs) 0.1 fCH_ = 9997Hz, 2Vp-p fSAMPLE = 53.25kHz 0 AMPLITUDE (dB) 0.2 CONVERSION TIME vs. SUPPLY VOLTAGE 21.0 MAX1108/09-14 0.4 0.3 INL (LSB) 20 MAX1108/09-13 0.5 MAX1108/09-15 INTEGRAL NONLINEARITY vs. CODE -80 20.0 19.5 19.0 18.5 -0.4 -100 -0.
PAGE 10
MAX1108/MAX1109 Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs VDD VDD DOUT DOUT 3kΩ CLOAD 3kΩ DOUT CLOAD CLOAD DGND DGND b) High-Z to VOL and VOH to VOL Figure 1. Load Circuits for Enable Time DOUT 3kΩ CLOAD DGND a) High-Z to VOH and VOL to VOH 3kΩ DGND a) VOH to High-Z b) VOL to High-Z Figure 2.
PAGE 11
Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs The input configuration selection also determines unipolar or bipolar conversion mode. The commonmode input range of CH0, CH1, and COM is 0 to +VDD. In unipolar mode, full scale is achieved when (SI - RI) = VREF; in bipolar mode, full scale is achieved when (SI - RI) = VREF / 2. In unipolar mode, SI must be higher than RI; in bipolar mode, SI can span above and below RI provided that it is within the common-mode range.
PAGE 12
MAX1108/MAX1109 Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs The serial interface provides easy connection to microcontrollers with SPI, QSPI and MICROWIRE serial interfaces at clock rates up to 2MHz. For SPI and QSPI, set CPOL = CPHA = 0 in the SPI control registers of the microcontroller. Figure 5 shows the MAX1108/MAX1109 common serial-interface connections. DOUT is active when CS is low and high impedance when CS is high. DOUT does not accept external voltages greater than VDD.
PAGE 13
Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs BIT 7 (MSB) BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0 (LSB) START SEL2 SEL1 SEL0 I/ECLK I/EREF REFSHDN SHDN BIT NAME 7 (MSB) START 6 5 4 SEL2 SEL1 SEL0 3 I/ECLK 1 = external clock, 0 = internal clock. The SAR can be driven by the internal oscillator, or with the SCLK signal. 2 I/EREF 1 = internal reference, 0 = external reference. Internal reference selects +2.048V (MAX1108) or +4.
PAGE 14
MAX1108/MAX1109 Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs initiated. The MSB successive-approximation bit decision is made on the rising edge of the seventh SCLK. On the falling edge of the eighth SCLK, the MSB is clocked out on the DOUT pin; on each of the next seven SCLK falling edges, the remaining bits of conversion are clocked out. Zeros are clocked out on DOUT after the LSB has been clocked out, until CS is disabled.
PAGE 15
Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs Quick Look To quickly evaluate the MAX1108/MAX1109’s analog performance, use the circuit of Figure 9. The device requires a control byte to be written to DIN before each conversion. Tying CS to GND and DIN to VDD feeds in control bytes of FFH. In turn, this triggers single-ended, unipolar conversions on CH0 in relation to COM in external clock mode without powering down between conversions.
PAGE 16
MAX1108/MAX1109 Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs to the SCLK pin; varying the analog input alters the result of conversion that is clocked out at the DOUT pin. A total of 10 clock cycles is required per conversion. In external clock mode, the first high bit clocked into DIN after the bit 5 (D5) of a conversion in progress is clocked onto the DOUT pin. Data Framing OR In internal clock mode, the first high bit clocked into DIN after the bit 4 (D4) is clocked onto the DOUT pin.
PAGE 17
Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs Table 4. Power-Down Modes of the MAX1108/MAX1109 BIT 2–BIT 0 OF CONTROL BYTE I/EREF REFSHDN OPERATING MODE SHDN 1 1 1 Device Active/Internal Reference Active 1 0 1 Device Active; Internal reference powered down after conversion, powered up at next start bit. 0 X 1 Device Active/External Reference Mode 1 0 0 Device and internal reference powered down after conversion, powered up at next start bit.
PAGE 18
MAX1108/MAX1109 Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs External Reference To use an external reference, set bit 2 (I/EREF) and bit 1 (REFSHDN) of control byte to 0 and connect the external reference (VREF between 1V and VDD) directly at the REF pin. The DC input impedance at REF is extremely high, consisting of leakage current only (typically 10nA).
PAGE 19
Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs TRANSISTOR COUNT: 2373 SYSTEM POWER SUPPLIES GND +3V/+5V 1µF 10Ω 0.1µF GND COM VDD MAX1108 MAX1109 DGND VDD DIGITAL CIRCUITRY Figure 13.
PAGE 20
Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages. e 10LUMAX.EPS MAX1108/MAX1109 Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs 4X S 10 10 INCHES H ÿ 0.50±0.1 0.6±0.1 1 1 0.6±0.1 BOTTOM VIEW TOP VIEW D2 MILLIMETERS MAX DIM MIN 0.043 A 0.006 A1 0.002 A2 0.030 0.037 0.120 D1 0.116 0.118 0.114 D2 0.116 0.120 E1 E2 0.114 0.118 H 0.187 0.199 L 0.