Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsData collecting ICsData acquisition IC - AD converter (ADC) External PDIP 28

_______________General Description

The MAX114/MAX118 are microprocessor-compatible,

8-bit, 4-channel and 8-channel analog-to-digital con-

verters (ADCs). They operate from a single +5V supply

and use a half-flash technique to achieve a 660ns con-

version time (1Msps). A power-down (PWRDN) pin

reduces current consumption typically to 1µA. The

devices return from power-down mode to normal oper-

ating mode in less than 200ns, allowing large supply-

current reductions in burst-mode applications (in burst

mode, the ADC wakes up from a low-power state at

specified intervals to sample the analog input signals).

Both converters include a track/hold, enabling the ADC

to digitize fast analog signals.

Microprocessor (µP) interfaces are simplified because the

ADC can appear as a memory location or I/O port without

external interface logic. The data outputs use latched,

three-state buffer circuitry for direct connection to an 8-bit

parallel µP data bus or system input port. The

MAX114/MAX118 input/reference configuration enables

ratiometric operation.

The 4-channel MAX114 is available in a 24-pin DIP or

SSOP. The 8-channel MAX118 is available in a 28-pin

DIP or SSOP. For +3V applications, refer to the

MAX113/MAX117 data sheet.

________________________Applications

High-Speed DSP Remote Data Acquisition

Portable Equipment Communications Systems

____________________________Features

♦ Single +5V Supply Operation

♦ 4 (MAX114) or 8 (MAX118) Analog Input Channels

♦ Low Power: 40mW (operating mode)

5µW (power-down mode)

♦ Total Unadjusted Error ≤1LSB

♦ Fast Conversion Time: 660ns per Channel

♦ No External Clock Required

♦ Internal Track/Hold

♦ 1MHz Full-Power Bandwidth

♦ Internally Connected 8th Channel Monitors

Reference Voltage (MAX118)

MAX114/MAX118

+5V, 1Msps, 4 & 8-Channel,

8-Bit ADCs with 1µA Power-Down

________________________________________________________________

Maxim Integrated Products

4-BIT

DAC

4-BIT

FLASH

ADC

(4MSBs)

4-BIT

FLASH

ADC

(4LSBs)

TIMING AND

CONTROL

ADDRESS

LATCH 

DECODE



REF+

THREE-

STATE

OUTPUT

DRIVERS

MUX

*IN7

*IN8

REF+

*IN6

*IN5

IN4

IN3

IN2

IN1

A1 A2 REF-

PWRDN

MODE

INT

WR/RDY

MAX114/MAX118

* MAX118 ONLY

_________________________________________________________Functional Diagram

19-1083; Rev 1; 8/96

PART

MAX114CNG

MAX114CAG

MAX114C/D 0°C to +70°C

0°C to +70°C

TEMP. RANGE PIN-PACKAGE

24 Narrow Plastic DIP

24 SSOP

Dice*

______________Ordering Information

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800

MAX114ENG

MAX114EAG

MAX114MRG -55°C to +125°C

-40°C to +85°C

-40°C to +85°C 24 Narrow Plastic DIP

24 SSOP

24 Narrow CERDIP**

Ordering Information continued on last page.

*Dice are specified at T

= +25°C, DC parameters only.

**Contact factory for availability.

Pin Configurations appear on last page.

Summary of content (12 pages)

PAGE 1
9-1083; Rev 1; 8/96 +5V, 1Msps, 4 & 8-Channel, 8-Bit ADCs with 1µA Power-Down ____________________________Features ♦ Single +5V Supply Operation ♦ 4 (MAX114) or 8 (MAX118) Analog Input Channels ♦ Low Power: 40mW (operating mode) 5µW (power-down mode) ♦ Total Unadjusted Error ≤1LSB ♦ Fast Conversion Time: 660ns per Channel ♦ No External Clock Required ♦ Internal Track/Hold ♦ 1MHz Full-Power Bandwidth ♦ Internally Connected 8th Channel Monitors Reference Voltage (MAX118) ________________________Application
PAGE 2
MAX114/MAX118 +5V, 1Msps, 4 & 8-Channel, 8-Bit ADCs with 1µA Power-Down ABSOLUTE MAXIMUM RATINGS VDD to GND ..............................................................-0.3V to +7V Digital Input Voltage to GND ......................-0.3V to (VDD + 0.3V) Digital Output Voltage to GND ...................-0.3V to (VDD + 0.3V) REF+ to GND..............................................-0.3V to (VDD + 0.3V) REF- to GND...............................................-0.3V to (VDD + 0.3V) IN_ to GND ..............
PAGE 3
+5V, 1Msps, 4 & 8-Channel, 8-Bit ADCs with 1µA Power-Down MAX114/MAX118 ELECTRICAL CHARACTERISTICS (continued) (VDD = +5V ±5%, REF+ = 5V, REF- = GND, Read Mode (MODE = GND), TA = TMIN to TMAX, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS LOGIC INPUTS Input High Voltage VINH Input Low Voltage VINL Input High Current IINH CS, WR, RD, PWRDN, A0, A1, A2 2.4 MODE 3.5 V CS, WR, RD, PWRDN, A0, A1, A2 0.8 MODE 1.
PAGE 4
MAX114/MAX118 +5V, 1Msps, 4 & 8-Channel, 8-Bit ADCs with 1µA Power-Down TIMING CHARACTERISTICS (VDD = +4.75V, TA = +25°C, unless otherwise noted.
PAGE 5
+5V, 1Msps, 4 & 8-Channel, 8-Bit ADCs with 1µA Power-Down EFFECTIVE NUMBER OF BITS vs. INPUT FREQUENCY (WR-RD MODE) 1.3 1.2 VDD = +4.75V 1.1 1.0 0.9 VDD = +5.25V 0.8 8.0 MAX114/118-02 1.4 EFFECTIVE NUMBER OF BITS 1.5 MAX114/118-01 7.5 7.0 6.5 fSAMPLE = 1MHz VIN = 4.96Vp-p VDD = +5V 0.7 6.0 0.6 -60 -20 60 20 1k 140 100 10k AVERAGE POWER CONSUMPTION vs. SAMPLING RATE USING PWRDN 1M SIGNAL-TO-NOISE RATIO 0 MAX114/118-03 40 30 20 VDD = 4.75V INPUT FREQUENCY = 195.8ksps VIN = 4.
PAGE 6
MAX114/MAX118 +5V, 1Msps, 4 & 8-Channel, 8-Bit ADCs with 1µA Power-Down ______________________________________________________________Pin Description PIN 6 NAME FUNCTION MAX114 MAX118 — 1 IN6 Analog Input Channel 6 — 2 IN5 Analog Input Channel 5 1 3 IN4 Analog Input Channel 4 2 4 IN3 Analog Input Channel 3 3 5 IN2 Analog Input Channel 2 4 6 IN1 Analog Input Channel 1 5 7 MODE Mode Selection Input. Internally pulled low with a 50µA current source.
PAGE 7
+5V, 1Msps, 4 & 8-Channel, 8-Bit ADCs with 1µA Power-Down Converter Operation The MAX114/MAX118 use a half-flash conversion technique (see Functional Diagram) in which two 4-bit flash ADC sections achieve an 8-bit result. Using 15 comparators, the flash ADC compares the unknown input voltage to the reference ladder and provides the upper four data bits.
PAGE 8
MAX114/MAX118 +5V, 1Msps, 4 & 8-Channel, 8-Bit ADCs with 1µA Power-Down In read mode, WR/RDY is configured as a status output (RDY), so it can drive the ready or wait input of a µP. RDY is an open-collector output (no internal pull-up) that goes low after the falling edge of CS and goes high at the end of the conversion. If not used, the WR/RDY pin can be left unconnected. The INT output goes low at the end of the conversion and returns high on the rising edge of CS or RD.
PAGE 9
+5V, 1Msps, 4 & 8-Channel, 8-Bit ADCs with 1µA Power-Down CS tCSS Figures 7a, 7b, and 7c show typical reference connections. The voltages at REF+ and REF- set the ADC’s analog input range (see Figure 10). The voltage at REFdefines the input that produces an output code of all zeros, and the voltage at REF+ defines the input that produces an output code of all ones. The internal resistance from REF+ to REF- can be as low as 1kΩ, and current will flow through it even when the MAX114/MAX118 are shut down.
PAGE 10
MAX114/MAX118 +5V, 1Msps, 4 & 8-Channel, 8-Bit ADCs with 1µA Power-Down to break this current path during power-down. The FET should have an on-resistance of less than 2Ω with a 5V gate drive. When REF- is switched, as in Figure 7d, a new conversion can be initiated after waiting a period of time equal to the power-up delay (tUP) plus the Nchannel FET’s turn-on time. Although REF+ is frequently connected to VDD, the circuit of Figure 7d uses a low-current, low-dropout, 4.096V voltage reference: the MAX874.
PAGE 11
+5V, 1Msps, 4 & 8-Channel, 8-Bit ADCs with 1µA Power-Down Conversion Rate OUTPUT CODE FULL-SCALE TRANSITION 11111111 11111110 11111101 The maximum sampling rate (fMAX) for the MAX114/ MAX118 is achieved in write-read mode (tRD < tINTL), and is calculated as follows: 1 fMAX = t WR + t RD + tRI + t ACQ fMAX = 1 250ns + 250ns + 150ns + 160ns 1LSB = VREF+ - VREF256 00000011 00000010 00000001 fMAX = 1.
PAGE 12
MAX114/MAX118 +5V, 1Msps, 4 & 8-Channel, 8-Bit ADCs with 1µA Power-Down __Ordering Information (continued) PART TEMP. RANGE ___________________Chip Information PIN-PACKAGE MAX118CPI 0°C to +70°C 28 Wide Plastic DIP MAX118CAI MAX118C/D MAX118EPI 0°C to +70°C 0°C to +70°C -40°C to +85°C 28 SSOP Dice* 28 Wide Plastic DIP MAX118EAI MAX118MJI -40°C to +85°C -55°C to +125°C 28 SSOP 28 Wide CERDIP** TRANSISTOR COUNT: 2011 *Dice are specified at TA = +25°C, DC parameters only.