Maxim MAX159BMJA, MAX157BEUA, MAX157BEPA, MAX157AMJA, MAX157AEUA Datasheet

19-1388; Rev 0; 11/98

+2.7V, Low-Power, 2-Channel, 108ksps, Serial 10-Bit ADCs in 8-Pin µMAX

General Description

The MAX157/MAX159 low-power, 10-bit analog-to-digi- tal converters (ADCs) are available in 8-pin µMAX and DIP packages. Both devices operate with a single +2.7V to +5.25V supply and feature a 7.4µs succes- sive-approximation ADC, automatic power-down, fast wake-up (2.5µs), an on-chip clock, and a high-speed, 3-wire serial interface.

Power consumption is only 3.2mW (VDD = +3.6V) at the maximum sampling rate of 108ksps. At slower throughput rates, the 0.2µA automatic shutdown further reduces power consumption.

The MAX157 provides 2-channel, single-ended operation and accepts input signals from 0 to VREF. The MAX159 accepts pseudo-differential inputs ranging from 0 to VREF. An external clock accesses data through the 3-wire serial interface, which is SPI™, QSPI™, and MICROWIRE™ compatible.

Excellent dynamic performance and low power, combined with ease of use and a small package size, make these converters ideal for battery-powered and data acquisition applications, or for other circuits with demanding power-consumption and space requirements. For pin-compatible 12-bit upgrades, see the MAX144/MAX145 data sheet.

	Applications
Battery-Powered Systems	Instrumentation
Portable Data Logging	Test Equipment
Isolated Data Acquisition	Medical Instruments
Process-Control Monitoring	System Supervision

Pin Configuration

TOP VIEW

VDD	1		8	SCLK
CH0 (CH+)	2	MAX157	7	DOUT
CH1 (CH-)	3	MAX159	6	CS/SHDN
GND	4		5	REF

μMAX/DIP

( ) ARE FOR MAX159 ONLY.

SPI and QSPI are trademarks of Motorola, Inc.

MICROWIRE is a trademark of National Semiconductor Corp.

Features

♦Single-Supply Operation (+2.7V to +5.25V)

♦Two Single-Ended Channels (MAX157) Single Pseudo-Differential Channel (MAX159)

♦Low Power

0.9mA (at 108ksps, +3V) 100µA (at 10ksps, +3V) 10µA (at 1ksps, +3V) <0.2µA (power-down mode)

♦Internal Track/Hold

♦108ksps Sampling Rate

♦SPI/QSPI/MICROWIRE-Compatible 3-Wire Serial Interface

♦Space-Saving 8-Pin µMAX Package

♦Pin-Compatible 12-Bit Upgrades Available

Ordering Information

	PART	TEMP.	PIN-		INL
		RANGE	PACKAGE		(LSB)
	MAX157ACUA	0°C to +70°C	8	µMAX	±0.5
	MAX157BCUA	0°C to +70°C	8	µMAX	±1
	MAX157ACPA	0°C to +70°C	8	Plastic DIP	±0.5
	MAX157BCPA	0°C to +70°C	8	Plastic DIP	±1
	MAX157AEUA	-40°C to +85°C	8	µMAX	±0.5
	MAX157BEUA	-40°C to +85°C	8	µMAX	±1
	MAX157AEPA	-40°C to +85°C	8	Plastic DIP	±0.5
	MAX157BEPA	-40°C to +85°C	8	Plastic DIP	±1
	MAX157AMJA	-55°C to +125°C	8 CERDIP*		±0.5
	MAX157BMJA	-55°C to +125°C	8 CERDIP*		±1
	MAX159ACUA	0°C to +70°C	8	µMAX	±0.5
	MAX159BCUA	0°C to +70°C	8	µMAX	±1
	MAX159ACPA	0°C to +70°C	8	Plastic DIP	±0.5
	MAX159BCPA	0°C to +70°C	8	Plastic DIP	±1
	MAX159AEUA	-40°C to +85°C	8	µMAX	±0.5
	MAX159BEUA	-40°C to +85°C	8	µMAX	±1
	MAX159AEPA	-40°C to +85°C	8	Plastic DIP	±0.5
	MAX159BEPA	-40°C to +85°C	8	Plastic DIP	±1
	MAX159AMJA	-55°C to +125°C	8 CERDIP*		±0.5
	MAX159BMJA	-55°C to +125°C	8 CERDIP*		±1

*Contact factory for availability.

________________________________________________________________ Maxim Integrated Products 1

MAX157/MAX159

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone]. For small orders, phone [phone].

MAX157/MAX159

+2.7V, Low-Power, 2-Channel,

108ksps, Serial 10-Bit ADCs in 8-Pin µMAX

ABSOLUTE MAXIMUM RATINGS

VDD to GND..............................................................		- 0.3V to +6V	Operating Temperature Ranges
CH0, CH1 (CH+, CH-) to GND...................	-0.3V to (VDD + 0.3V)		MAX157/MAX159_C_A .......................................	0°C to +70°C
REF to GND................................................	-0.3V to (VDD + 0.3V)		MAX157/MAX159_E_A ....................................	-40°C to +85°C
Digital Inputs to GND ...............................................		- 0.3V to +6V	MAX157/MAX159_MJA.................................	-55°C to +125°C
DOUT to GND.............................................	-0.3V to (VDD + 0.3V)		Storage Temperature Range .............................	-60°C to +150°C
DOUT Sink Current ............................................................		25mA	Lead Temperature (soldering, 10sec) .............................	+300°C
Continuous Power Dissipation (TA = +70°C)
µMAX (derate 4.1mW/°C above +70°C) ......................		330mW
Plastic DIP (derate 9.09mW/°C above +70°C)		............727mW
CERDIP (derate 8.00mW/°C above +70°C).................		640mW

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS

(VDD = +2.7V to +5.25V, VREF = 2.5V, 0.1µF capacitor at REF, fSCLK = 2.17MHz, 16 clocks/conversion cycle (108ksps), CH- = GND for MAX159, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)

	PARAMETER	SYMBOL	CONDITIONS	MIN	TYP	MAX	UNITS
	DC ACCURACY (Note 1)
	Resolution	RES		10			Bits
	Relative Accuracy (Note 2)	INL	MAX15_A			±0.5	LSB
			MAX15_B			±1
	Differential Nonlinearity	DNL	No missing codes over temperature			±0.5	LSB
	Offset Error					±2	LSB
	Gain Error (Note 3)					±2	LSB
	Gain Temperature Coefficient		External reference, VREF = 2.5V		±0.8		ppm/°C
	Channel-to-Channel Offset				±0.02		LSB
	Matching
	Channel-to-Channel Gain				±0.02		LSB
	Matching

DYNAMIC SPECIFICATIONS (fIN (sine wave) = 10kHz, VIN = 2.5Vp-p, 108ksps, external fSCLK = 2.17MHz, CH- = GND for MAX159)

Signal-to-Noise Ratio plus	SINAD		66	dB
Distortion
Total Harmonic Distortion	THD		-70	dB
(including 5th-order harmonic)
Spurious-Free Dynamic Range	SFDR		70	dB
Channel-to-Channel Crosstalk		fIN = 65kHz, VIN = 2.5Vp-p (Note 4)	-75	dB
Small-Signal Bandwidth		-3dB rolloff	2.25	MHz
Full-Power Bandwidth			1.0	MHz

2 _______________________________________________________________________________________

+2.7V, Low-Power, 2-Channel, 108ksps, Serial 10-Bit ADCs in 8-Pin µMAX

ELECTRICAL CHARACTERISTICS (continued)

(VDD = +2.7V to +5.25V, VREF = 2.5V, 0.1µF capacitor at REF, fSCLK = 2.17MHz, 16 clocks/conversion cycle (108ksps), CH- = GND for MAX159, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)

PARAMETER	SYMBOL	CONDITIONS	MIN	TYP	MAX	UNITS
CONVERSION RATE
		External clock, fSCLK = 2.17MHz, 16 clock	7.4
Conversion Time (Note 5)	tCONV	cycles per conversion				µs
		Internal clock	5		7
T/H Acquisition Time	tACQ				2.5	µs
Aperture Delay				25		ns
Aperture Jitter				<50		ps
		External clock mode	0.1		2.17	MHz
Serial Clock Frequency	fSCLK					MHz
		Internal clock mode, for data transfer only	0		5
ANALOG INPUTS
Analog Input Voltage Range	VIN		0		VREF	V
(Note 6)
Multiplexer Leakage Current		On/off-leakage current, VIN = 0 to VDD		±0.01	±1	µA
Input Capacitance	CIN			16		µA
EXTERNAL REFERENCE
Input Voltage Range (Note 7)	VREF		0	VDD + 50mV		V
Input Current		VREF = 2.5V		100	140	µA
Input Resistance			18	25		kΩ
Shutdown REF Input Current				0.01	10	µA
DIGITAL INPUTS (CS/SHDN, SCLK) AND		DIGITAL OUTPUT (DOUT)
Input High Voltage	VIH	VDD ≤ 3.6V	2.0			V
		VDD > 3.6V	3.0
Input Low Voltage	VIL				0.8	V
Input Hysteresis	VHYS			0.2		V
Input Leakage Current	IIN	VIN = 0 or VDD			±1	µA
Input Capacitance	CIN	(Note 8)			15	pF
Output Low Voltage	VOL	ISINK = 5mA			0.4	V
		ISINK = 16mA		0.5
Output High Voltage	VOH	ISOURCE = 0.5mA	VDD - 0.5			V
Three-State Output Leakage		CS/SHDN = VDD			±10	µA
Current
Three-State Output Capacitance	COUT	CS/SHDN = VDD (Note 8)			15	pF

MAX157/MAX159

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MAX157/MAX159

+2.7V, Low-Power, 2-Channel,

108ksps, Serial 10-Bit ADCs in 8-Pin µMAX

ELECTRICAL CHARACTERISTICS (continued)

(VDD = +2.7V to +5.25V, VREF = 2.5V, 0.1µF capacitor at REF, fSCLK = 2.17MHz, 16 clocks/conversion cycle (108ksps), CH- = GND for MAX159, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)

PARAMETER	SYMBOL	CONDITIONS	MIN	TYP	MAX	UNITS
POWER REQUIREMENTS
Positive Supply Voltage	VDD		+2.7		+5.25	V
Positive Supply Current	IDD	Operating mode		0.9	2.0	mA
Positive Supply Current	IDD	Shutdown, CS/SHDN = GND		0.2	5	µA
Power-Supply Rejection	PSR	VDD = 2.7V to 5.25V, full-scale input		±0.15		mV
(Note 9)

TIMING CHARACTERISTICS (Figure 7)

(VDD = +2.7V to +5.25V, VREF = 2.5V, 0.1µF capacitor at REF, fSCLK = 2.17MHz, 16 clocks/conversion cycle (108ksps), CH- = GND for MAX159, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)

PARAMETER	SYMBOL	CONDITIONS	MIN	TYP	MAX	UNITS
Wake-Up Time	tWAKE		2.5			µs
CS/SHDN Fall to Output Enable	tDV	CL = 100pF (Figure 1)			120	ns
CS/SHDN Rise to Output	tTR	CL = 100pF (Figure 1)			120	ns
Disable
SCLK Fall to Output Data Valid	tDO	CL = 100pF	20		120	ns
SCLK Clock Frequency	fSCLK	External clock	0.1		2.17	MHz
		Internal clock, SCLK for data transfer only	0		5
		External clock	215
SCLK Pulse Width High	tCH					ns
		Internal clock, SCLK for data transfer only	50
		(Note 8)
		External clock	215
SCLK Pulse Width Low	tCL					ns
		Internal clock, SCLK for data transfer only	50
		(Note 8)
SCLK to CS/SHDN Setup	tSCLKS		60			ns
CS/SHDN Pulse Width	tCS		60			ns

Note 1: Tested at VDD = +2.7V.

Note 2: Relative accuracy is the deviation of the analog value at any code from its theoretical value after full-scale range has been calibrated.

Note 3: Offset nulled.

Note 4: The on channel is grounded; the sine wave is applied to off channel (MAX157 only).

Note 5: Conversion time is defined as the number of clock cycles times the clock period; clock has 50% duty cycle. Note 6: The common-mode range for the analog inputs is from GND to VDD (MAX159 only).

Note 7: ADC performance is limited by the converter’s noise floor, typically 300µVp-p. Note 8: Guaranteed by design. Not subject to production testing.

Note 9: Measured as VFS(2.7V) - VFS(5.25V).

4 _______________________________________________________________________________________

+2.7V, Low-Power, 2-Channel, 108ksps, Serial 10-Bit ADCs in 8-Pin µMAX

Typical Operating Characteristics

(VDD = +3.0V, VREF = 2.5V, 0.1µF capacitor at REF, fSCLK = 2.17MHz, 16 clocks/conversion cycle (108ksps); CH- = GND for MAX159; TA = +25°C, unless otherwise noted.)

				SUPPLY CURRENT																							SUPPLY CURRENT																												SUPPLY CURRENT
				vs. SUPPLY VOLTAGE																							vs. TEMPERATURE																											vs. SAMPLING RATE
	1500															toc01				1500																	toc02	10,000																																							toc03
			VREF	= VDD																			V	REF =		VDD																					V		REF		= VDD
A)(μ																MAX157/159		A)(μ																			MAX157/159		A)(μ																																						MAX157/159
			RL =	∞																			R	L = ∞																								CODE				=			1010101000
	1300																																								1000						CL =				50pF
			CL =	50pF																1250			C	L = 50pF
CURRENT	1100		CODE	= 1010101000														CURRENT					CODE = 1010101000																CURRENT		100
																				1000
SUPPLY																		SUPPLY																					SUPPLY
	900																																								10
																				750
	700																																								1
																				500
	500																																								0.1
	2.5		3.0 3.5			4.0			4.5			5.0			5.5					-60			-40 -20				0 20 40 60 80					100 120				140								0.1			1							10					100						1k 10k 100k
						VDD (V)																					TEMPERATURE (°C)																												SAMPLING RATE (sps)
												SHUTDOWN CURRENT																										SHUTDOWN CURRENT
												vs. SUPPLY VOLTAGE																											vs. TEMPERATURE
						1000																			toc04							1000																													toc05
									VREF =		VDD																								VREF = VDD
																									MAX157/159																																				MAX157/159
				(nA)		800																								(nA)		800
				CURRENT		600																								CURRENT		600
				SHUTDOWN																										SHUTDOWN
						400																										400
						200																										200
						0																										0
						2.5			3.0			3.5			4.0			4.5		5.0			5.5									-60				-40		-20 0			20			40			60 80							100			120		140
															VDD (V)																								TEMPERATURE (°C)
								OFFSET ERROR vs. SUPPLY VOLTAGE																											OFFSET ERROR vs. TEMPERATURE
						0.20																			MAX157/159 toc06							0.20																													MAX157/159 toc07
						0.15																								ERROR (LSB)		0.15
				ERROR (LSB)
						0.10																										0.10
				OFFSET																										OFFSET
						0.05																										0.05
						0																										0
						2.5			3.0			3.5			4.0			4.5		5.0			5.5									-60				-35		-10			15			40			65							90			115		140
															VDD (V)																								TEMPERATURE (°C)

MAX157/MAX159

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