CAT2300 SENSEFET) Current Monitor for 0.9 V - 1.5 V Bus Description CAT2300 is a controller for SENSEFET® MOSFET current monitoring in high-side switch applications. CAT2300 provides current mirroring and ON/OFF control for SENSEFET MOSFETs. Exact control and matching of the Sense output of the SENSEFET with the Kelvin voltage insures accurate current monitoring over a couple of decades of current. Designed for use with NTMFS4833NST1G, NTMFS4854NST1G or similar SENSEFET MOSFETs from ON Semiconductor, CAT2300 is the single chip alternative to discrete circuits for monitoring and controlling 0.9 V − 1.5 V power busses. When teamed with a SENSEFET, CAT2300 will track currents up to 25 A and resolve currents below 100 mA. CAT2300 provides logic level ON/OFF control of the power MOSFET and its own internal circuitry, reducing power consumption to virtually zero milliwatts. Packaged in a space saving low profile 2 x 3 mm TDFN, CAT2300 operates over the full industrial temperature range of −40°C to +85°C. http://onsemi.com TDFN−8 VP2 SUFFIX CASE 511AK PIN CONFIGURATION Sense 1 KS EN Kelvin VDD Gate GND (Top View) Features • Precision Current Measurement of 0.9 V − 1.5 V Power Supply Rails • ON/OFF Power FET Control with Soft−start • Sense Current Mirroring to 70 mA • • • • IMEAS (equal to 25 A flowing in the power bus) User Adjustable Current to Voltage Conversion Ratio 150 mV Typical Matching between Kelvin and Sense Leads Less than 1 mA Current Consumption in Shutdown Mode This Device is Pb−Free, Halogen Free/BFR Free and RoHS Compliant Typical Applications MARKING DIAGRAM F3T LAA YM G F3T L AA Y M G • Portable Computers • Backplane Bus Control • Power Distribution = Specific Device Code = Assembly Location Code = Assembly Lot Number = (Last Two Digits) = Production Year (Last Digit) = Production Month (1−9, O, N, D) = Pb−Free Microdot ORDERING INFORMATION Power Bus Enable System Load SENSEFET CAT2300 Device Package Marking Shipping† CAT2300 TDFN F3T 3,000 / Tape & Reel †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specification Brochure, BRD8011/D. IMEASURE Figure 1. System Application ORDERING INFORMATION See detailed ordering and shipping information in the package dimensions section on page 7 of this data sheet. © Semiconductor Components Industries, LLC, 2012 November, 2012 − Rev. 2 1 Publication Order Number: CAT2300/D CAT2300 Gate Kelvin KS Sense VREG 1 250 mA + VDD − 0 IMEAS EN GND Figure 2. Simplified Block Diagram Table 1. PIN FUNCTION DESCRIPTION Pin No. Pin Name 1 Sense 2 KS 3 Kelvin Connects to Kelvin pin of the SENSEFET. Serves as the reference point for Sense lead biasing. 4 Gate Connects to Gate of the SENSEFET and controls SENSEFET operation. 5 GND Electrical ground for IC. 6 VDD External voltage supply for driving the gate of the SENSEFET and power supply for CAT2300 internal circuitry via an internal voltage regulator. 7 EN Enable: High true logic input. Turns ON SENSEFET and CAT2300’s internal circuitry. A logic LOW on EN grounds Gate, shutting off the SENSEFET and shuts down the internal current source and mirroring circuitry. 8 IMEAS PAD Function Connects to Sense pin of SENSEFET and directs sensed current to IMEAS output. Kelvin Sense; a Kelvin connection for the current mirror control amplifier. This connection must be made directly to Sense on the SENSEFET package. Do not share any trace length with CAT2300’s Sense lead. Sensed current output. A resistor between IMEAS and ground develops a voltage proportional to the current flowing through the SENSEFET. Backside paddle is internally connected to GND. This pad may be left floating but if connected with PCB it must be to the ground plane of circuitry which is also grounded. Table 2. ABSOLUTE MAXIMUM RATINGS (Note 1) Symbol Value Unit VDD 6.5 V Gate ±15 mA VK, EN, Sense, KS, Kelvin, IMEAS 6.5 V Junction Temperature 150 °C Parameter VDD Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. 1. Guaranteed by design. Table 3. RECOMMENDED OPERATING CONDITIONS Parameter Symbol Value Unit VK 0.9 to 1.5 V VDD 5 V Maximum Junction Temperature TJUNCTION 125 °C Ambient Temperature Range TAMBIENT −40 to +85 °C VK VDD http://onsemi.com 2 CAT2300 Table 4. PACKAGE THERMAL PERFORMANCE Package Symbol Test Conditions qJA TDFN−8 qJA Max Unit °C/W 35 160 1 oz Copper Thickness, 100 mm2 qJC Typ 160 1 oz Copper Thickness, 100 mm2 qJC SOIC−8 Min °C/W 25 Table 5. DC ELECTRICAL CHARACTERISTICS (VK = 0.9 – 1.5 V; VDD = +5 V; TAMBIENT = −40°C to +85°C, TJUNCTION = −40°C to +125°C, unless otherwise specified.) Limits Parameter Kelvin voltage Symbol Test Conditions Min Typ Max Units VK 0.9 1.5 V Gate Drive input voltage VDD 4.5 5.5 V Supply Current on VDD pin IVDD 1 mA EN = logic 0 EN = logic 1 Gate drive Sourcing IGATE Gate drive Sinking Offset Voltage Input Bias Current; Kelvin and KS inputs VGATE = VDD – 1 V VGATE = 0.6 V VOS 65 77 100 mA −235 −280 −330 mA 7 9.6 13 mA ±150 ±300 mV 100 150 nA VOS = VKELVIN − VSENSE VK = 0.9 V to 1.5 V IK Power Supply Rejection Ratio PSRR IMEAS output current IMEAS 0 70 70 mA db Output voltage of IMEAS amplifier VO_IM 0 VK – 0.1 V LOGIC Low level input voltage VIL EN 0.9 1.1 1.26 V High level input voltage VIH EN 1.4 1.65 1.9 V Low level input current IIL EN, VDD = 0 V or 5.5 V 2 mA High level input current IIH EN, VDD = 0 V or 5.5 V 2 mA Max Units Hysteresis 0.55 V Table 6. AC OPERATING CHARACTERISTICS (VK = 0.9 V – 1.5 V; VDD = 5 V; TAMBIENT = −40°C to +85°C, TJUNCTION = −40°C to +125°C, unless otherwise specified.) Limits Parameter Symbol IMEAS output rise time tR IMEAS output fall time tF IMEAS Settling time tS Test Conditions Min Typ 20 W, 100 pF, VK = 1.5 V ISENSE : 2 mA – 70 mA 38 ms 33 ms EN = Logic 0³1, ISENSE = 1 mA 30 ms EN = Logic 0³1, ISENSE = 70 mA 50 ms http://onsemi.com 3 CAT2300 TYPICAL PERFORMANCE CHARACTERISTICS IBus VMEAS 50 ms / div Figure 3. Load Step: 1 A – 10 A PIN DESCRIPTION Sense Careful layout is critical in achieving full SENSEFET perfomance. PCB trace resistance can no longer be ignored as it can be in typical low current circuit designs. Microvolt offsets (mV) produce meaningful errors in current ratio tracking. A few milliohms of trace resistance carrying a few milliamps of current produces microvolts of potential difference between CAT2300 and the SENSEFET. To circumvent this error CAT2300 provides a Kelvin lead (KS) for monitoring the SENSEFET’s Sense pin. Under no circumstances should the KS connection share any portion of the current path between the sense pins of CAT2300 and the SENSEFET. Doing so will degrade measurement accuracy. Sense connects directly to the SENSEFET’s Sense pin and directs the sensed current to the IMEAS output. Sense is controlled by an amplifier with a FET follower stage to maintain Sense at exactly the Kelvin voltage, thus insuring accuracy of the SENSEFET’s mirror current. KS KS = Kelvin Sense; a Kelvin connection for the mirroring amplifier. Current measurement accuracy is dependent upon the voltage match between the SENSEFET’s Sense and Kelvin leads. To minimize voltage losses in the PCB trace between CAT2300 and the SENSEFET, a Kelvin connection for the control amplifier is provided. KS must be a dedicated connection, shared by no other circuitry, and tied directly to the Sense pin on of the SENSEFET. Kelvin Kelvin connects directly to the SENSEFET’s Kelvin pin and acts the reference voltage for CAT2300’s mirroring circuit. It too must be a dedicated connection, shared by no other circuitry. SENSEFET Gate Gate connects to the SENSEFET’s Gate pin and controls the SENSEFET’s operation. Gate is controlled by EN: a logic 1 turns the SENSEFET ON, a logic 0 turns it OFF. When ON, voltage is applied to the SENSEFET’s gate via a current source inside CAT2300. By controlling the gate drive current a controlled turn-ON is achieved. Faster turn-on times can be done by adding a supplemental current source to augment the internal current source. Placing a resistor between VDD and Gate will provide extra current and boost turn-on speeds. For a softer turn-on characteristic, add capacitance between the SENSEFET’s Gate and Source pins; approximately 1 nF for every ms of increased delay. When switching OFF the SENSEFET, Gate provides a strong pull-down, 7.5 mA typical, so the SENSEFET will be switched off quickly. SENSEFET SENSEFET Figure 4. Current Sense http://onsemi.com 4 CAT2300 VDD EN VDD provides gate drive for the SENSEFET and power for CAT2300’s internal circuitry and must be +5 V. Enable is a high true logic input controlling the SENSEFET’s ON/OFF state. A logic high on EN turns the switch ON; a logic low turns it OFF. Bus turn-ON time is controlled by the FET’s input gate capacitance and the drive current applied to the gate. To minimize power consumption EN disables the internal gate drive current source and current mirroring circuitry whenever the SENSEFET is OFF. IMEAS IMEAS is the mirror current output. Placing a resistor between IMEAS and ground produces a voltage proportional to IBUS. The maximum voltage producible at IMEAS is the Kelvin voltage (VK) – 0.1 V. This sets a limitation on the maximum value of RMEAS. R MEAS + ǒV K * 0.1 VǓ I SENSE + CSR ǒV K * 0.1 VǓ I bus where: CSR = Current Sensing Ratio taken from the SENSEFET data sheet. Ibus = Max current through the SENSEFET. NTMF4834NS VIN Kelvin Drain Source Sense Ibus Gate Gate VOUT ISense Kelvin KS Sense VREG 1 250 mA + VDD − IMEAS 0 VMEAS EN CAT2300 GND Figure 5. Typical Application http://onsemi.com 5 CAT2300 PACKAGE DIMENSIONS TDFN8, 2x3 CASE 511AK−01 ISSUE A D A e b E2 E PIN#1 IDENTIFICATION A1 PIN#1 INDEX AREA D2 TOP VIEW SYMBOL MIN SIDE VIEW NOM A 0.70 0.75 0.80 0.00 0.02 0.05 A2 0.45 0.55 0.65 A2 0.20 REF A3 b 0.20 0.25 0.30 D 1.90 2.00 2.10 D2 1.30 1.40 1.50 E 2.90 3.00 3.10 E2 1.20 1.30 1.40 e L BOTTOM VIEW MAX A1 A3 FRONT VIEW 0.50 TYP 0.20 0.30 L 0.40 Notes: (1) All dimensions are in millimeters. (2) Complies with JEDEC MO-229. http://onsemi.com 6 CAT2300 ORDERING INFORMATION Part Number CAT2300VP2−GT3 2. 3. 4. 5. Temperature Range Package Quantity per Reel (Note 5) Package Marking −40°C to +85°C TDFN 3,000 F3T All packages are RoHS−compliant (Lead−free, Halogen−free). The standard lead finish is NiPdAu pre−plated (PPF). For additional package and temperature options, please contact your nearest ON Semiconductor Sales office. For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. SENSEFET is a registered trademark of Semiconductor Components Industries, LLC ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent−Marking.pdf. SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. 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This literature is subject to all applicable copyright laws and is not for resale in any manner. PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT: Literature Distribution Center for ON Semiconductor P.O. Box 5163, Denver, Colorado 80217 USA Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada Fax: 303−675−2176 or 800−344−3867 Toll Free USA/Canada Email: [email protected] N. American Technical Support: 800−282−9855 Toll Free USA/Canada Europe, Middle East and Africa Technical Support: Phone: 421 33 790 2910 Japan Customer Focus Center Phone: 81−3−5817−1050 http://onsemi.com 7 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative CAT2300/D