LM12458 - 12-Bit Plus Sign Data Acquisition System with Self-Calibration

Datasheet	Packaging	Samples & Pricing	Reliability	Knowledge Base

Features

•	Three operating modes: 12-bit + sign, 8-bit + sign, and "watchdog"
•	Single-ended or differential inputs
•	Built-in Sample-and-Hold and 2.5V bandgap reference
•	Instruction RAM and event sequencer
•	8-channel multiplexer
•	32-word conversion FIFO
•	Programmable acquisition times and conversion rates
•	Self-calibration and diagnostic mode
•	8- or 16-bit wide data bus microprocessor or DSP interface

Key Specification

(f_CLK = 5 MHz; 8 MHz, H)

Resolution	12-bit + sign or 8-bit + sign
13-bit conversion time	8.8 µs, 5.5 µs (H) (max)
9-bit conversion time	4.2 µs, 2.6 µs (H) (max)
13-bit Through-put rate	88k samples/s (min),140k samples/s (H) (min)
Comparison time ("watchdog" mode)	2.2 µs (max),1.4 µs (H) (max)
ILE	±1 LSB (max)
V_IN range	GND to V_A⁺
Power Consumption	30 mW, 34 mW (H) (max)
Stand-by mode	50 µW (typ)
Single supply	3V to 5.5V

General Description

The LM12458, and LM12H458 are highly integrated Data Acquisition Systems. More...

Applications

•	Data Logging
•	Instrumentation
•	Process Control
•	Energy Management
•	Inertial Guidance

Parameters Values

Resolution 12 bits

Input Channels 8

Interface Type Parallel

Differential Input Yes

INL (LSB) +/-1.0

Max KSample Rate 114 ksps

Min Supply Voltage 3 Volt

Max Supply Voltage 5.5 Volt

Reference Source Internal

Temperature Min -40 deg C

Temperature Max 85 deg C

Power Down Yes

Input Sample/Hold Yes

Special Features Undefined

Data Converter Type ADC

Max Sample Rate 0.114 MSPS

Typical Performance

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WEBENCH Live Simulation!

LM12458 Webench™ Custom Design/Analyze/Build It

Also Recommended

LM12H458▲	Higher Speed (5.5us)
LM12L458▲	Lower Voltage/Power (3.3V)

Block Diagram

click for larger image

Datasheet

RoHS Compliance Information	Size in Kbytes	Date
LM12454/LM12458/LM12H458 12-Bit + Sign Data Acquisition System with Self-Calibration	1195 Kbytes	16-Feb-06	Download

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Package Availability, Models, Samples & Pricing

Part Number

Package

Factory Lead Time

Models

Samples &
Electronic
Orders

Budgetary Pricing

Std
Pack
Size

Package
Marking
Format

Type

Pins

Spec.

MSL
Rating

Peak
Reflow

RoHS
Report

CAD
Symbols

Weeks

Qty

$US each

LM12458CIV

PLCC

NOPB
STD

3
2A

245
220

RoHS

N/A

Full production

N/A

1K+

$14.40

rail
of
25

NSUZXYYTTE#
LM12458CIV

12 weeks

1000

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM12458CIVF	NONE	NATIONAL SEMICONDUCTOR	05 Sep 2006
LM12458EVAL	NONE	NONE	07 Jun 2000
LM12458MEL/883	NONE	NONE	03 Mar 2004

General Description

The LM12458, and LM12H458 are highly integrated Data Acquisition Systems. Operating on just 5V, they combine a fully-differential self-calibrating (correcting linearity and zero errors) 13-bit (12-bit + sign) analog-to-digital converter (ADC) and sample-and-hold (S/H) with extensive analog functions and digital functionality. Up to 32 consecutive conversions, using two's complement format, can be stored in an internal 32-word (16-bit wide) FIFO data buffer. An internal 8-word RAM can store the conversion sequence for up to eight acquisitions through the LM12(H)458's eight-input multiplexer. The obsolete LM12454 has a four-channel multiplexer, a differential multiplexer output, and a differential S/H input. The LM12(H)458 can also operate with 8-bit + sign resolution and in a supervisory "watchdog" mode that compares an input signal against two programmable limits.

Programmable acquisition times and conversion rates are possible through the use of internal clock-driven timers. The reference voltage input can be externally generated for absolute or ratiometric operation or can be derived using the internal 2.5V bandgap reference.

All registers, RAM, and FIFO are directly addressable through the high speed microprocessor interface to either an 8-bit or 16-bit data bus. The LM12(H)458 includes a direct memory access (DMA) interface for high-speed conversion data transfer.

Additional applications information can be found in applications notes AN-906, AN-947 and AN-949.

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM12458CIV	CS150	1	15120	67	0	1067500	4	302906039

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.

Application Notes

Title	Size in Kbytes	Date
AN-947: Interfacing the LM12458 Data Acquisition System to the MC68HC11AX Microcontroller	279 Kbytes	5-Aug-95	Download
AN-906: Interfacing the LM12454/8 Data Acquisition System Chips to Microprocessors and Microcontrollers	561 Kbytes	5-Aug-95	Download
AN-906 (Japanese): Interfacing the LM12454/8 Data Acquisition System Chips to Microprocessors and Microcontrollers	880 Kbytes
AN-949: Interfacing the LM12454/8 Data Acquisition System Chips to the 80C51 Family of Microcontrollers	579 Kbytes	5-Aug-95	Download

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[Information as of 8-Nov-2009]