LM9044 Lambda Sensor Interface Amplifier General Description The LM9044 is a precision differential amplifier specifically designed for operation in the automotive environment. Gain accuracy is guaranteed over the entire automotive temperature range (b40§ C to a 125§ C) and is factory trimmed prior to package assembly. The input circuitry has been specifically designed to reject common-mode signals as much as 3V below ground on a single positive power supply. This facilitates the use of sensors which are grounded at the engine block while the LM9044 itself is grounded at chassis potential. An external capacitor sets the maximum operating frequency of the amplifier, thereby filtering high frequency transients. Both inputs are protected against accidental shorting to the battery and against load dump transients. The input impedance is typically 1 MX. The output op amp is capable of driving capacitive loads and is fully protected. Also, internal circuitry has been pro- vided to detect open circuit conditions on either or both inputs and force the output to a ‘‘home’’ position (a ratio of the external reference voltage). Features Y Y Y Y Y Y Y Normal circuit operation guaranteed with inputs up to 3V below ground on a single supply Gain factory trimmed and guaranteed over temperature ( g 3% of full-scale from b40§ C to a 125§ C) Low power consumption (typically 1 mA) Fully protected inputs Input open circuit detection Operation guaranteed over the entire automotive temperature range (b40§ C to a 125§ C) Single supply operation Schematic and Connection Diagrams TL/H/6744 – 1 Plastic Chip Carrier Package Order Number LM9044V See NS Package Number V20A *Pins 1, 3, 4, 6, 8, 9, 10, 11, 13, 14, 16, 18, 19 are trim pins and should be left floating. C1995 National Semiconductor Corporation TL/H/6744 TL/H/6744 – 6 Top View RRD-B30M115/Printed in U. S. A. LM9044 Lambda Sensor Interface Amplifier February 1995 Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. VCC Supply Voltage (RVCC e 15 kX) b 40§ C to a 125§ C b 65§ C to a 150§ C Soldering Information Plastic Chip Carrier Package Vapor Phase (60 seconds) Infrared (15 seconds) g 60V VREF Supply Voltage DC Input Voltage (Either Input) Input Transients (Note 1) Power Dissipation (see Note 6) Output Short Circuit Duration Operating Temperature Range Storage Temperature Range b 0.3V to a 6V b 3V to a 16V 215§ C 220§ C See AN-450 ‘‘Surface Mounting Methods and Their Effect on Product Reliability’’ for other methods of soldering surface mount devices. g 60V 1350 mW Indefinite Electrical Characteristics VCC e 12V, VREF e 5V, b40§ C s TA s 125§ C unless otherwise noted Parameter Differential Voltage Gain (Note 2) Conditions VDIF e 0.5V b 1V s VCM s a 1V (Note 3) Min Typ Max 4.41 4.50 4.59 b2 0 2 VDIF e 0.5V, b3VsVCMs a 1V Gain Error (Note 5) 0.95 1.20 g 0.38 0 1.20 b 25 b 65 V/V %/FS 4.00 MX mA g 0.38 0sVDIFs1V b 1V s VCM s a 1V 3 g 0.65 0sVDIFs1V b 3V s VCM s a 1V Inverting Input Bias Current 4.64 MX 0.70 0sVDIFs1V b 1V s VCM s a 1V 4.50 3.00 0sVDIFs1V b 3V s VCM s a 1V Non-Inverting Input Bias Current Units Max %/FS b3 osVDIFs1V b 1V s VCM s a 1V Typ V/V 4.36 0sVDIFs1V b 1V s VCM s a 1V 0sVDIFs1V b 3V s VCM s a 1V Differential Input Resistance Min g 1.5 b 100 mA mA 0VsVDIFs1V b 3V s VCM s a 1V b 45 b 150 mA VCC Supply Current VCC e 12V, RVCC e 15k 300 500 mA VREF Supply Current 4.75VsVREFs5.5V 0.5 1.0 mA Common-Mode Voltage Range (Note 4) b1 DC Common-Mode Rejection Ratio Input Referred b 1V s VCM s a 1V VDIF e 0.5V Open Circuit Output Voltage One or Both Inputs Open, b1VsVCMs a 1V 1 50 60 0.371 0.397 0.423 5.0 b3 1 V dB b 3V s VCM s a 1V XVREF 0.365 0.397 0.429 XVREF Short Circuit Output Current Output Grounded 1.0 2.7 VCC Power Supply Rejection Ratio VCC e 12V, RVCC e 15K VDIF e 0.5V 50 65 mA dB VREF Power Supply Rejection Ratio VREF e 5 VDC VDIF e 0.5V 60 74 dB Note 1: This test is performed with a 1000X source impedance. Note 2: These parameters are guaranteed and 100% production tested. Note 3: These parameters will be guaranteed but not 100% production tested. Note 4: The LM9044 has been designed to common-mode to b 3V, but production testing is only performed at g 1V. Note 5: Gain error is given as a percent of full-scale. Full-scale is defined as 1V at the input and 4.5V at the output. Note 6: For operation in ambient temperatures above 25§ C the device must be derated based on a maximum junction temperature of 150§ C and a thermal resistance of 93§ C/W junction to ambient. 2 Typical Performance Characteristics Non-Inverting Input Bias Current vs Temperature Inverting Input Bias Current vs Temperature VREF Supply Current vs Temperature VCC Supply Current vs Temperature Short Circuit Output Current vs Temperature Differential Gain vs Temperature TL/H/6744 – 3 3 Typical Performance Characteristics (Continued) Voltage Gain vs Frequency CMRR vs Frequency VREF Power Supply Rejection VCC Power Supply Rejection TL/H/6744 – 4 Test Circuit TL/H/6744 – 5 4 5 LM9044 Lambda Sensor Interface Amplifier Physical Dimensions inches (millimeters) Plastic Chip Carrier Package Order Number LM9044V NS Package Number V20A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation 1111 West Bardin Road Arlington, TX 76017 Tel: 1(800) 272-9959 Fax: 1(800) 737-7018 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Europe Fax: (a49) 0-180-530 85 86 Email: cnjwge @ tevm2.nsc.com Deutsch Tel: (a49) 0-180-530 85 85 English Tel: (a49) 0-180-532 78 32 Fran3ais Tel: (a49) 0-180-532 93 58 Italiano Tel: (a49) 0-180-534 16 80 National Semiconductor Hong Kong Ltd. 13th Floor, Straight Block, Ocean Centre, 5 Canton Rd. Tsimshatsui, Kowloon Hong Kong Tel: (852) 2737-1600 Fax: (852) 2736-9960 National Semiconductor Japan Ltd. Tel: 81-043-299-2309 Fax: 81-043-299-2408 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.