ZXCT1030EV2 Evaluation Board User Guide Doc: Issue: Date: Page: ZXCT1030EV2-UG 2.0 8 January 2009 1 of 12 ` Figure 1 Evaluation board components' layout DESCRIPTION The ZXCT1030EV2 is intended for the evaluation of the ZXCT1030 device. The ZXCT1030 is a high side current sense monitor containing an internal reference and comparator with a non-latching output. Using this device eliminates the need to disrupt the ground plane when sensing a load current. The wide input voltage range of 20V down to as low as 2.2V makes it suitable for a range of applications. Dynamics and supply current are optimized for the processing of fast pulses associated with switch mode applications. The evaluation board is delivered with the values shown in Figure 2 below. As can be seen, RS consists of two resistors (R1 and R2) which are configured in parallel such that either one or both resistors could be connected by completing the solder-bridge link next to each one. R2 (0.5R) is connected by default. R3 consists of two pads with a hole in each pad and provides means for connecting an external RS. With the values shown, the board produces an output of 5V/A The printed circuit board contains redundant component positions which are provided for (but not fitted) to enable the user to experiment if needed. ZDB546R1 Doc: Issue: Date: Page: ZXCT1030EV2 Evaluation Board User Guide Supply V1 ZXCT1030EV2-UG 2.0 8 January 2009 2 of 12 ILOAD RS (R1//R2//R3) V2 0R5 R7 10k V CC R8 o/c (150k) 3 VCC 1 VCC R4 10k 2 S+ S- ZXCT1030 GND OUT VREF 6 7 VOUT VOUT 8 Flag Flag VCC + VTRP 5 4 GND R5 10k R6 o/c o/c = Open Circuit GND GND Figure 2 Equivalent circuit diagram for evaluation board ZXCT1030EV2 VCC range 2.2V to 20V Supply Range 2.2V to 20V V Flag VFLG VILH = VTRP = 10 ⋅ RS ⋅ I LOAD( HIGH ) VILH VOUT VS+ VSL Figure 3 Device' response versus varying supply ZDB546R1 ZXCT1030EV2 Evaluation Board User Guide Doc: Issue: Date: Page: ZXCT1030EV2-UG 2.0 8 January 2009 3 of 12 ORDERING INFORMATION ORDER NUMBER ZXCT1030EV2 Please note evaluation boards are subject to availability and qualified leads. PAD NAMES AND DEFINITIONS NAME DESCRIPTION V1 V2 VOUT FLAG Supply Voltage Connection to Load Output Voltage Tripped flag (low when tripped) GND 0V / Ground SL1 – SL5 Optional Solder Links VCC Device supply Both the input voltage (voltage on V1) and VCC range for the ZXCT1030EV2 is from 2.2V to 20V. ZDB546R1 Doc: Issue: Date: Page: ZXCT1030EV2 Evaluation Board User Guide ZXCT1030EV2-UG 2.0 8 January 2009 4 of 12 ZXCT1030EV2 Summary R3 R1 0.05R V1 SL1 ILOAD Supply V2 SL2 R2 0.5R R7 10k V CC R8 150k 3 VCC 1 VCC 2 S+ S- ZXCT1030 GND OUT 7 VOUT VREF 6 SL3 SL4 SL5 VCC + VTRP 5 8 Flag - R4 10k VOUT Flag 4 GND R5 10k R6 UDF UDF = User DeFined GND GND Figure 4 Actual circuit diagram for ZXCT1030EV2 Sense resistor The board has been designed with two selectable values of sense resistor. The value of the sense resistor can be chosen by using the solder links SL1 and SL2. The board is also tracked for a user-defined through-hole resistor (R3). The 50mΩ resistor (R1) is selected by shorting SL1 and opening SL2. This results in an output of 0.5 V/A. The 500mΩ resistor (R2) is selected by shorting SL2 and opening SL1, resulting in an output of 5V/A. If both links are shorted the effective resistance is 45.45 mΩ giving an output of 454.5 mV/A. ZDB546R1 ZXCT1030EV2 Evaluation Board User Guide Doc: Issue: Date: Page: ZXCT1030EV2-UG 2.0 8 January 2009 5 of 12 If both links are open, the optional leaded resistor R3 can be exclusively used as the sense resistor. The maximum power dissipation rating of the resistor must be appropriate to the load current level. For further information on choosing a value of sense resistor please refer to the ZXCT1030 datasheet. Trip current sensitivity and its adjustment The current at which the ZXCT1030EV2 trips (FLAG goes low) is changed by changing the reference voltage that is fed into the VCOMP pin. A resistor position, R6, is available to enable this. Adding R6 to form a potential divider with R5 causes the on-chip reference to be attenuated allowing the ZXCT1030 to trip at a lower current. This trip current is given by, ITRIP = VREF ⋅ R 6 10 ⋅ RS (R 5 + R 6) It can be seen from above that the term, VREF ⋅ R 6 = VTRP (R 5 + R 6 ) Therefore, ITRIP = VTRP 10 ⋅ RS Equation 1 All the values above, with the exception of R6, are either known or can be determined by the user. Therefore determine R6 as follows, 1. 2. 3. Choose the trip current, ITRIP. Compute VTRP (Volts) from Equation 1 Compute R6 (kΩ) from, R5 10k = R6 = VREF 1.24 − 1 − 1 VTRP VTRP ZDB546R1 ZXCT1030EV2 Evaluation Board User Guide Doc: Issue: Date: Page: ZXCT1030EV2-UG 2.0 8 January 2009 6 of 12 Configuration table for ZXCT1030EV2 LOAD CURRENT (A) 1.0 1.0 1.0 RSENSE (mΩ) VOUT (V) SOLDER LINK CONFIGURATION 50 500 45.45 0.5 5 0.454 Short SL2 Short SL1 Short SL1 & SL2 Configuration for different LOAD currents. The board can be configured for different load currents by changing the SMD resistors or fitting a suitable wire ended resistor and opening both solder links. It is important to ensure an appropriate value of RS is selected to obtain the desired accuracy for a given output current. The value of VOUT is the voltage dropped across the sensing resistor multiplied by 10. Choosing a larger value for RS gives a higher output voltage for a given current resulting in better resolution but at the expense of increased voltage drop and higher dissipation in RS. The ZXCT1030 is optimized for values of VSENSE around 100mV. Accuracy The ZXCT1030 has a typical 3% accuracy for a VSENSE of 100mV. The accuracy of the output voltage will be influenced by the tolerance of the external sense used. The ZXCT1030EV2 utilizes 1% sense resistors. COMPONENTS LIST Ref Value Package Part Number R1 R2 R4,5,7 R8 ZXCT I/O’s 50mΩ 500mΩ 10k 150k 2512 2512 0805 0805 SO-8 Test loops ZDB546R1 LR2512-R050FW LR2512-R500FW Manufacturer Welwyn Welwyn Notes SMD Sense Resistor 1% SMD Sense Resistor 1% ZXCT1030N8 100-108 Zetex Hughes Rapid 17-1835 ZXCT1030EV2 Evaluation Board User Guide Doc: Issue: Date: Page: ZXCT1030EV2-UG 2.0 8 January 2009 7 of 12 Required Equipment 1. 2. 3. 1 x 20R 5W resistor (load). 2 x voltage adjustable bench PSUs with voltage and current monitoring and current limiting. 2 x DVMs (DVM1 to read up to 15V, resolution 10mV, and DVM2 to read up to 300mA, resolution 1mA) SET-UP AND TEST The board is preset to give an output Voltage of 1V for a load current of 200mA (SL2 is shorted to connect in R2, a 500mΩ, sense resistor). The board will fail if any of the tests below do not meet the specification indicated, at any stage. Set-up 1. 2. 3. 4. 5. 6. 7. 8. Ensure SL2 and SL4 are shorted. Switch the outputs of PSU1 and PSU2 to ‘OFF’ Set PSU1 to 15V ±0.1V and limit its current to any value between 10mA and 40mA. Set PSU2 to 0v and limit it’s current to 300mA. Connect PSU1 +ve to VCC and -ve to GND. Connect PSU2 +ve to V1 and -ve to GND. Connect DVM1 +ve to FLAG and -ve to GND. Connect one end of a 20R 5W resistor to GND. Connect the other end to the –ve of DVM2 and connect the +ve (current range terminal) of DVM2 to V2. (See diagram). 9. Switch on PSU1, followed by PSU2. Test Procedure 1. Measure the FLAG voltage indicated on DVM1. It must be <500mV. 2. Increase the PSU2 voltage slowly and monitor the FLAG voltage until the point at which the FLAG voltage goes ‘HIGH’. The FLAG voltage should measure >14V. 3. Read the PSU2 voltage. It must be 2.6V +100mV, -300mV. 4. Increase the PSU2 voltage slowly and monitor the FLAG voltage until the point at which the FLAG voltage goes ‘LOW’. The FLAG voltage must measure <500mV. 5. Read the PSU2 voltage. It must be 5.15V ± 200mV. 6. Measure the current through the load, on DVM2. It must be 248mA ± 8mA. 7. Remove the +ve terminal of DVM1 from the FLAG pin and connect it to the Vout pin. Vout must measure 1.24V ± 40mV. 8. Decrease the PSU2 voltage until DVM2 reads a current of 200mA ± 1mA through the load. Vout must then read 1.0v ± 40mV. END OF TEST ZDB546R1 Doc: Issue: Date: Page: ZXCT1030EV2 Evaluation Board User Guide ZXCT1030EV2 V1 20R 5W V2 A VOUT PSU2 VCC FLAG GND GND PSU1 Figure 5 Test diagram for ZXCT1030EV2 EVALUATION BOARD ZDB546R1 ZXCT1030EV2-UG 2.0 8 January 2009 8 of 12 DVM ZXCT1030EV2 Evaluation Board User Guide Intentionally Blank ZDB546R1 Doc: Issue: Date: Page: ZXCT1030EV2-UG 2.0 8 January 2009 9 of 12 ZXCT1030EV2 Evaluation Board User Guide Intentionally Blank ZDB546R1 Doc: Issue: Date: Page: ZXCT1030EV2-UG 2.0 8 January 2009 10 of 12 ZXCT1030EV2 Evaluation Board User Guide Intentionally Blank ZDB546R1 Doc: Issue: Date: Page: ZXCT1030EV2-UG 2.0 8 January 2009 11 of 12 ZXCT1030EV2 Evaluation Board User Guide Doc: Issue: Date: Page: ZXCT1030EV2-UG 2.0 8 January 2009 12 of 12 Definitions Product change Zetex Semiconductors reserves the right to alter, without notice, specifications, design, price or conditions of supply of any product or service. Customers are solely responsible for obtaining the latest relevant information before placing orders. Applications disclaimer The circuits in this design/application note are offered as design ideas. It is the responsibility of the user to ensure that the circuit is fit for the user’s application and meets with the user’s requirements. No representation or warranty is given and no liability whatsoever is assumed by Zetex with respect to the accuracy or use of such information, or infringement of patents or other intellectual property rights arising from such use or otherwise. Zetex does not assume any legal responsibility or will not be held legally liable (whether in contract, tort (including negligence), breach of statutory duty, restriction or otherwise) for any damages, loss of profit, business, contract, opportunity or consequential loss in the use of these circuit applications, under any circumstances. Life support Zetex products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the Chief Executive Officer of Zetex Semiconductors plc. As used herein: A. Life support devices or systems are devices or systems which: 1. are intended to implant into the body or 2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labelling can be reasonably expected to result in significant injury to the user. B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or to affect its safety or effectiveness. Reproduction The product specifications contained in this publication are issued to provide outline information only which (unless agreed by the company in writing) may not be used, applied or reproduced for any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned. Terms and Conditions All products are sold subjects to Zetex’ terms and conditions of sale, and this disclaimer (save in the event of a conflict between the two when the terms of the contract shall prevail) according to region, supplied at the time of order acknowledgement. For the latest information on technology, delivery terms and conditions and prices, please contact your nearest Zetex sales office. Quality of product Zetex is an ISO 9001 and TS16949 certified semiconductor manufacturer. To ensure quality of service and products we strongly advise the purchase of parts directly from Zetex Semiconductors or one of our regionally authorized distributors. For a complete listing of authorized distributors please visit: www.zetex.com/salesnetwork Zetex Semiconductors does not warrant or accept any liability whatsoever in respect of any parts purchased through unauthorized sales channels. ESD (Electrostatic discharge) Semiconductor devices are susceptible to damage by ESD. Suitable precautions should be taken when handling and transporting devices. The possible damage to devices depends on the circumstances of the handling and transporting, and the nature of the device. The extent of damage can vary from immediate functional or parametric malfunction to degradation of function or performance in use over time. Devices suspected of being affected should be replaced. Green compliance Zetex Semiconductors is committed to environmental excellence in all aspects of its operations which includes meeting or exceeding regulatory requirements with respect to the use of hazardous substances. Numerous successful programs have been implemented to reduce the use of hazardous substances and/or emissions. All Zetex components are compliant with the RoHS directive, and through this it is supporting its customers in their compliance with WEEE and ELV directives. Product status key: “Preview” “Active” “Last time buy (LTB)” “Not recommended for new designs” “Obsolete” Datasheet status key: “Draft version” “Provisional version” “Issue” Future device intended for production at some point. Samples may be available Product status recommended for new designs Device will be discontinued and last time buy period and delivery is in effect Device is still in production to support existing designs and production Production has been discontinued This term denotes a very early datasheet version and contains highly provisional information, which may change in any manner without notice. This term denotes a pre-release datasheet. It provides a clear indication of anticipated performance. However, changes to the test conditions and specifications may occur, at any time and without notice. This term denotes an issued datasheet containing finalized specifications. However, changes to specifications may occur, at any time and without notice. Europe Americas Asia Pacific Corporate Headquarters Zetex GmbH Kustermann-park Balanstraße 59 D-81541 München Germany Telefon: (49) 89 45 49 49 0 Fax: (49) 89 45 49 49 49 [email protected] Zetex Inc 700 Veterans Memorial Highway Hauppauge, NY 11788 USA Zetex (Asia Ltd) 3701-04 Metroplaza Tower 1 Hing Fong Road, Kwai Fong Hong Kong Zetex Semiconductors plc Zetex Technology Park, Chadderton Oldham, OL9 9LL United Kingdom Telephone: (1) 631 360 2222 Fax: (1) 631 360 8222 [email protected] Telephone: (852) 26100 611 Fax: (852) 24250 494 [email protected] Telephone (44) 161 622 4444 Fax: (44) 161 622 4446 [email protected] © 2006 Published by Zetex Semiconductors plc. ZDB546R1