AS1524_1 AMSCO
Document overview
- Manufacturer or author: Provided By digicamel.com
- PDF pages: 22
Technical content
Datasheet sections
- 1 General Description
- 2 Key Features
- 3 Applications
- 4 Pinout
- 5 Absolute Maximum Ratings
- 6 Electrical Characteristics
- 7 Typical Operating Characteristics
- 8 Detailed Description
- 9 Application Information
- 10 Package Drawings and Markings
- 11 Ordering Information
1 General Description
Figure 1. AS1524/AS1525 - Block Diagram
2 Key Features
3 Applications
sumption and single-supply requirements. Table 1. Standard Products
4 Pinout
Figure 2. Pin Assignments (Top View) Table 2. Pin Description 1 VDD Positive Supply Voltage. +2.7V to +5.25V. Note: Bypass with a 0.1µF capacitor to GND. 5R E F External Reference Voltage Input. Sets the analog voltage range. Note: Bypass with a 4.7µF capacitor to GND.
6 CNVST
hold mode and begins a conversion. Note: This pin goes high impedance once data has been fully clocked out. 8S C L K Serial Clock Input. Clocks out data at DOUT with the MSB first.
5 REF
8 SCLK
5 Absolute Maximum Ratings
Table 3. Absolute Maximum Ratings State Surface Mount Devices”.
6 Electrical Characteristics
TAMB = TMIN to TMAX (unless otherwise specified). Typical Values at TAMB = +25ºC. Unipolar Mode (AS1524). Table 4. Electrical Characteristics
- The absolute input voltage range for the analog inputs is from GND to VDD.
Table 4. Electrical Characteristics (Continued)
7 Typical Operating Characteristics
VDD = 5V; VREF = 2.5V, fSCLK = 8MHz(50% duty), CREF = 4.7µF, TAMB = +25ºC (unless otherwise specified). Figure 5. Integral Nonlinearity vs. Digital Output Code Fi gure 6. Differential Nonlinearity vs. Digital Output Code Figure 7. Supply Current vs. Supply Voltage Figure 8. Supply Current vs. Temperature Figure 9. Supply Current vs. Temperature, VDD = 3V Figure 10. Supply Current vs. Sampling Rate
Figure 17. FFT @ 10kHz
8 Detailed Description
(1-channel, true differential). input capacitor is connected to GND (AS1525) or AIN- (AS1524). Figure 18. Equivalent Input Circuit tPWR of 1µs is the power-up time of the device. placing a 1µF capacitor between the positive and negative analog inputs. selected for the next conversion.
by using undersampling techniques. more than 50mV for accurate conversions. Note: If an off-channel analog input voltage exceeds the supply voltages, the input current should be limited to 2mA. be clocked out before CNVST transitions again. data is always straight binary. bipolar transfer function for the AS1524. Code transitions occur halfway between successive-integer LSB values. Figure 21. AS1524/AS1525 Unipolar Transfer Function
1 LSB = V
Figure 22. AS1524 Bipolar Transfer Function
9 Application Information
later, the device completes conversion, enters shutdown, and MSB is available at DOUT. reference input structure allows a voltage range of +1V to VDD + 50mV.
- Use a general-purpose I/O line on the CPU to hold CNVST low between conversions.
- Drive CNVST high to acquire AIN1(AS1525) or unipolar mode (AS1524). To acquire AIN2 (AS1525) or bipolar
mode (AS1524), drive CNVST low and high again.
- Hold CNVST high for 1.4µs.
- Drive CNVST low and wait approximately 3.7µs for conversion to complete. After 3.7µs, the MSB is available
- Activate SCLK for a minimum of 12 rising clock edges. DOUT transitions on SCLK’s falling edge and is avail-
AS1525 and select a clock frequency up to 8MHz. Figure 23. SPI Serial Interface Connections
Table 6. SSPCON Register Settings 0: Disables serial port and configures these pins as I/O port pins. CKP Bit 4 0 Clock Polarity Select Bit. CKP = 0 for SPI master mode selection. Table 7. SSPSTAT Register Settings
The AS1524/AS1525 require proper layout and design procedures for optimum performance. ! Use printed circuit boards; wirewrap boards should not be used. ! Digital traces should not run beneath the AS1524/AS1525. low impedance and as short as possible for noise-free operation. together as possible, and their traces should be kept short, direct, and wide. ! Keep the voltage feedback network very close to the device, within 5mm (0.2”) of the pin. them using grounded copper traces. Figure 30. Recommended Ground Design
The devices are available in a 8-pin TDFN (3x3mm) package. Figure 31. 8-pin TDFN (3x3mm) Packagee
- Figure 31 is shown for illustration only.
- All dimensions are in millimeters; angles in degrees.
- Dimensioning and tolerancing conform to ASME Y14.5 M-1994.
- N is the total number of terminals.
- The terminal #1 identifier and terminal numbering convention shall conform to JEDEC 95-1, SPP-012. Details of ter-
- Dimension b applies to metallized terminal and is measured between 0.15mm and 0.30mm from the terminal tip.
- ND refers to the maximum number of terminals on side D.
- Unilateral coplanarity zone applies to the exposed heat sink slug as well as the terminals
The devices are available as the standard products shown in Table 8. Note: All products are RoHS compliant and Pb-free. Table 8. Ordering Information
www.austriamicrosystems.com Revision 1.02 22 - 22 AS1524/AS1525 Datasheet Copyrights Copyright © 1997-2009, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. All products and companies mentioned are trademarks or registered trademarks of their respective companies. Disclaimer Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location. The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services. Contact Information Headquarters austriamicrosystems AG Tobelbaderstrasse 30 A-8141 Unterpremstaetten, Austria Tel: +43 (0) 3136 500 0 Fax: +43 (0) 3136 525 01 For Sales Offices, Distributors and Representatives, please visit: http://www.austriamicrosystems.com/contact