MAX148BEAP-T Maxim Integrated Products, MAX148BEAP-T Datasheet

no-image

MAX148BEAP-T

Manufacturer Part Number
MAX148BEAP-T
Description
Manufacturer
Maxim Integrated Products
Datasheet
The MAX148/MAX149 10-bit data-acquisition systems
combine an 8-channel multiplexer, high-bandwidth
track/hold, and serial interface with high conversion
speed and low power consumption. They operate from a
single +2.7V to +5.25V supply, and sample to 133ksps.
Both devices’ analog inputs are software configurable for
unipolar/bipolar and single-ended/differential operation.
The 4-wire serial interface connects directly to SPI™/
QSPI™ and MICROWIRE™ devices without external
logic. A serial-strobe output allows direct connection to
TMS320-family digital signal processors. The MAX148/
MAX149 use either the internal clock or an external serial-
interface clock to perform successive-approximation
analog-to-digital conversions.
The MAX149 has an internal 2.5V reference, while the
MAX148 requires an external reference. Both parts have
a reference-buffer amplifier with a ±1.5% voltage-
adjustment range.
These devices provide a hard-wired SHDN pin and a
software-selectable power-down, and can be pro-
grammed to automatically shut down at the end of a con-
version. Accessing the serial interface automatically
powers up the MAX148/MAX149, and the quick turn-on
time allows them to be shut down between all conver-
sions. This technique can cut supply current to under
60µA at reduced sampling rates.
The MAX148/MAX149 are available in a 20-pin DIP and a
20-pin SSOP.
For 4-channel versions of these devices, see the
MAX1248/MAX1249 data sheet.
Portable Data Logging
Medical Instruments
Pen Digitizers
Pin Configuration appears at end of data sheet.
________________________Applications
19-0464; Rev 2; 5/98
SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp.
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
________________________________________________________________ Maxim Integrated Products
+2.7V to +5.25V, Low-Power, 8-Channel,
General Description
Data Acquisition
Battery-Powered Instruments
Process Control
Ordering Information continued at end of data sheet.
____________________________Features
__________Typical Operating Circuit
Contact factory for availability of alternate surface-mount
packages.
MAX148ACPP
MAX148BCPP
MAX148ACAP
MAX148BCAP
8-Channel Single-Ended or 4-Channel
Differential Inputs
Single-Supply Operation: +2.7V to +5.25V
Internal 2.5V Reference (MAX149)
Low Power: 1.2mA (133ksps, 3V supply)
SPI/QSPI/MICROWIRE/TMS320-Compatible
4-Wire Serial Interface
Software-Configurable Unipolar or Bipolar Inputs
20-Pin DIP/SSOP Packages
PART
ANALOG
INPUTS
0.01 F
0V TO
+2.5V
4.7 F
Serial 10-Bit ADCs
54µA (1ksps, 3V supply)
1µA (power-down mode)
CH0
CH7
VREF
REFADJ
TEMP. RANGE
MAX149
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
Ordering Information
SSTRB
DGND
AGND
DOUT
SHDN
SCLK
COM
V
DIN
CS
DD
20 Plastic DIP
20 Plastic DIP
20 SSOP
20 SSOP
PIN-PACKAGE
+3V
0.1 F
MISO (SI)
V
I/O
SCK (SK)
MOSI (SO)
DD
CPU
V
SS
(LSB)
±1/2
±1
±1/2
±1
INL
1

Related parts for MAX148BEAP-T

MAX148BEAP-T Summary of contents

Page 1

... Pin Configuration appears at end of data sheet. SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp. ________________________________________________________________ Maxim Integrated Products For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 408-737-7600 ext. 3468. ...

Page 2

Low-Power, 8-Channel, Serial 10-Bit ADCs ABSOLUTE MAXIMUM RATINGS V to AGND, DGND................................................. -0. AGND to DGND ...................................................... -0.3V to 0.3V CH0–CH7, COM to AGND, DGND ............ -0. VREF, REFADJ to AGND ........................... ...

Page 3

Low-Power, 8-Channel, ELECTRICAL CHARACTERISTICS (continued +2.7V to +5.25V; COM = 0V MAX149—4.7µF capacitor at VREF pin; MAX148—external reference, VREF = 2.500 V applied to VREF pin; T otherwise noted.) PARAMETER SYMBOL CONVERSION RATE ...

Page 4

Low-Power, 8-Channel, Serial 10-Bit ADCs ELECTRICAL CHARACTERISTICS (continued +2.7V to +5.25V; COM = 0V SCLK MAX149—4.7µF capacitor at VREF pin; MAX148—external reference, VREF = 2.500 V applied to VREF pin; T otherwise noted.) ...

Page 5

Low-Power, 8-Channel, TIMING CHARACTERISTICS (V = +2.7V to +5.25V MIN PARAMETER SYMBOL Acquisition Time DIN to SCLK Setup DIN to SCLK Hold SCLK Fall to Output Data Valid CS Fall ...

Page 6

Low-Power, 8-Channel, Serial 10-Bit ADCs ____________________________Typical Operating Characteristics (continued 3.0V, VREF = 2.500V 2.0MHz SCLK SUPPLY CURRENT vs. SUPPLY VOLTAGE 2. CODE = 1010101000 C = 50pF LOAD ...

Page 7

Low-Power, 8-Channel, ______________________________________________________________Pin Description PIN NAME 1–8 CH0–CH7 Sampling Analog Inputs Ground reference for analog inputs. COM sets zero-code voltage in single-ended mode. Must be 9 COM stable to ±0.5LSB. Three-Level Shutdown Input. Pulling SHDN low shuts ...

Page 8

Low-Power, 8-Channel, Serial 10-Bit ADCs _______________Detailed Description The MAX148/MAX149 analog-to-digital converters (ADCs) use a successive-approximation conversion technique and input track/hold (T/H) circuitry to convert an analog signal to a 10-bit digital output. A flexible seri- al interface ...

Page 9

Low-Power, 8-Channel +2.500V ANALOG 0.01µF INPUT +3V +3V 2.5V V OUT C1 1000pF 0.1µF MAX872 COMP OPTIONAL FOR MAX149, REQUIRED FOR MAX148 * FULL-SCALE ANALOG INPUT, CONVERSION RESULT = $FFF (HEX) Figure 5. Quick-Look Circuit ...

Page 10

Low-Power, 8-Channel, Serial 10-Bit ADCs Table 1. Control-Byte Format BIT 7 BIT 6 BIT 5 (MSB) START SEL2 SEL1 BIT NAME DESCRIPTION The first logic “1” bit after CS goes low defines the beginning of the control ...

Page 11

Low-Power, 8-Channel, Table 3. Channel Selection in Differential Mode (SGL SEL2 SEL1 SEL0 CH0 ...

Page 12

Low-Power, 8-Channel, Serial 10-Bit ADCs CS t CSS t CSH SCLK DIN t DV DOUT Figure 7. Detailed Serial-Interface Timing CS t SDV SSTRB SCLK Figure 8. External Clock Mode SSTRB Detailed Timing ...

Page 13

Low-Power, 8-Channel, CS SCLK UNI/ DIN SEL2 SEL1 SEL0 BIP START SSTRB DOUT A/D STATE IDLE Figure 9. Internal Clock Mode Timing CS t CSH SSTRB SCLK PD0 CLOCK IN DOUT NOTE: FOR ...

Page 14

Low-Power, 8-Channel, Serial 10-Bit ADCs Table 4. Typical Power-Up Delay Times REFERENCE- REFERENCE BUFFER BUFFER COMPENSATION MODE Enabled Internal Enabled Internal Enabled External Enabled External Disabled — Disabled — bit of the control byte (the PD0 bit) ...

Page 15

Low-Power, 8-Channel SCLK DIN S CONTROL BYTE 0 DOUT SSTRB Figure 11a. External Clock Mode, 15 Clocks/Conversion Timing SCLK S CONTROL BYTE 0 DIN DOUT Figure 11b. External Clock Mode, 16 Clocks/Conversion ...

Page 16

Low-Power, 8-Channel, Serial 10-Bit ADCs CLOCK MODE SETS INTERNAL CLOCK MODE DIN DOUT SSTRB CONVERSION MODE Figure 12b. Timing Diagram Power-Down Modes, Internal Clock Table 5. Software Power-Down and ...

Page 17

Low-Power, 8-Channel, AVERAGE SUPPLY CURRENT vs. CONVERSION RATE (USING FASTPD) 10,000 R = LOAD CODE = 1010101000 1000 8 CHANNELS 100 100 1k CONVERSION RATE (Hz) Figure 14b. MAX149 Supply Current vs. ...

Page 18

Low-Power, 8-Channel, Serial 10-Bit ADCs (ZEROS) DIN FULLPD 1.21V REFADJ 0V 2.50V VREF 0V Figure 15. MAX149 FULLPD/FASTPD Power-Up Sequence +3.3V 24k 510k 100k 12 0.01µF Figure 16. MAX149 Reference-Adjust Circuit Lowest Power at ...

Page 19

Low-Power, 8-Channel, Table 7. Full Scale and Zero Scale UNIPOLAR MODE Full Scale VREF + COM OUTPUT CODE FS = VREF + COM 011 . . . 111 2 011 . . . 110 ZS = COM ...

Page 20

Low-Power, 8-Channel, Serial 10-Bit ADCs 1 CH0 2 CH1 3 CH2 4 ANALOG CH3 MAX148 INPUTS MAX149 5 CH4 6 CH5 7 CH6 8 CH7 9 COM 10 SHDN Figure 20. MAX148/MAX149 QSPI Connections, External Reference CS ...

Page 21

Low-Power, 8-Channel, CS SCLK DIN START SEL2 SEL1 SSTRB DOUT Figure 22. TMS320 Serial-Interface Timing Diagram High-Speed Digital Interfacing with QSPI The MAX148/MAX149 can interface with QSPI using the circuit in Figure 2.0MHz, CPOL ...

Page 22

... TEMP. RANGE PIN-PACKAGE MAX148AEPP -40°C to +85°C 20 Plastic DIP MAX148BEPP -40°C to +85°C 20 Plastic DIP MAX148AEAP -40°C to +85°C 20 SSOP MAX148BEAP -40°C to +85°C 20 SSOP MAX148AMJP -55°C to +125°C 20 CERDIP* MAX148BMJP -55°C to +125°C 20 CERDIP* MAX149ACPP 0°C to +70°C 20 Plastic DIP MAX149BCPP 0° ...

Page 23

Low-Power, 8-Channel, ________________________________________________________Package Information ______________________________________________________________________________________ Serial 10-Bit ADCs 23 ...

Page 24

... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 24 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 1998 Maxim Integrated Products Printed USA ...

Related keywords