19-4747; Rev 0; 9/09 High-Side MOSFET Driver for HB LED Drivers and DC-DC Applications Features The MAX15054 is a high-side, n-channel MOSFET driver for high-voltage applications capable of switching at high frequencies. This device is controlled by a CMOS logiclevel signal referenced to ground and features a very short (12ns, typ) propagation delay from input to output. The high-voltage operation and high source/sink-current capability make the MAX15054 ideal for HB LED drivers and DC-DC converters. S Input Voltage on High-Side n-Channel MOSFET Up to 60V S Up to 13.5V Logic Input Independent of Supply Voltage S 2A Peak Source and Sink Current S 12ns Propagation Delay S Rise and Fall Times of 6ns while Driving 1000pF The MAX15054 is well suited to complement other Maxim LED driver products such as the MAX16814, MAX16838, MAX16833, MAX16834, and MAX16826. The MAX15054 adds a high-side driver to those products that include only a low-side driver; it then allows for buck-boost configurations for multistring drivers similar to the MAX16814, MAX16838, and MAX16826, and for buck-boost conversion with output referenced to ground for single-string drivers such as the MAX16834 and MAX16833. Capacitance S Low Input Capacitance S Low-Side and High-Side Undervoltage Protection S Allows Buck-Boost Topology Referred to Ground for LED Drivers and DC-DC Converters S Allows Buck-Boost Topology for Multistring LED Drivers S 6-Pin SOT23 Package The MAX15054 is available in the industry-standard 6-pin SOT23 package and operates over the -40NC to +125NC automotive temperature range. Ordering Information Applications PART HB LED Drivers for Single and Multiple Strings TEMP RANGE MAX15054AUT+ -40NC to +125NC LED Backlight Drivers PINPACKAGE TOP MARK 6 SOT23 ACOM +Denotes a lead(Pb)-free/RoHS-compliant package. High-Side Driver for DC-DC Converters (Buck, Buck-Boost, Half-Bridge, Full-Bridge) Pin Configuration appears at end of data sheet. Typical Operating Circuits VIN D1 BST VDD CBST C1 MAX15054 HDRV Q1 LX GND HI L1 D2 R1 C2 IN R8 C5 GATE NDRV CFB DRAIN R2 D3 EN VCC R9 OV C3 OUT1 R3 C4 VDRV OUT2 MAX16838 FLT DIM CS RT COMP R4 SGND R7 ISET PGND LEDGND R6 R5 C4 Typical Operating Circuits continued at end of data sheet. ________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX15054 General Description MAX15054 High-Side MOSFET Driver for HB LED Drivers and DC-DC Applications ABSOLUTE MAXIMUM RATINGS VDD to GND.............................................................. -0.3V to +6V Thermal Resistance (Note 1) LX to GND................................................................. -2V to +65V Junction-to-Ambient Thermal Resistance (BJA)..........115NC/W HDRV to LX.................................................-0.3V to (VDD + 0.3V) Junction-to-Case Thermal Resistance (BJC).................80NC/W BST to LX.................................................................. -0.3V to +6V Operating Temperature Range......................... -40NC to +125NC HI to GND............................................................... -0.3V to +15V Maximum Junction Temperature......................................+150NC dV/dt at LX......................................................................... 50V/ns Storage Temperature Range............................. -65NC to +150NC Peak Current into HDRV (< 100ns)....................................... Q2A Lead Temperature (soldering, 10s)..................................+300NC Continuous Current into HDRV . .................................... Q100mA Continuous Power Dissipation (TA = +70NC) 6-Pin SOT23 (derate 8.7mW/NC above +70NC)..........695.7mW Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VDD = VBST = 5V, VLX = VGND = 0V, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = TJ = +25°C, unless otherwise noted.) (Note 2) PARAMETER SYMBOL CONDITIONS Operating Supply Voltage VDD VDD Quiescent Supply Current IDD No switching BST Quiescent Supply Current IBST BST Operating Supply Current IBSTO VDD Undervoltage Lockout Threshold VDD_UVLO MIN MAX V 40 75 FA No switching 65 125 FA fSW = 500kHz, no load 0.3 1.3 mA 4.22 4.56 V VDD rising 3.92 0.2 VBST_ UVLO UNITS 5.5 VDD Undervoltage Lockout Threshold Hysteresis BST-to-LX Undervoltage Lockout Threshold TYP 4.6 BST rising 3.54 BST-to-LX Undervoltage Lockout Threshold Hysteresis 3.82 V 4.1 0.2 V V LOGIC INPUT (HI) HI Logic-High Threshold VIH HI Logic-Low Threshold VIL 3.9 HI Logic-Input Hysteresis V 1.8 V +2 FA 0.9 HI Input Current IIN HI Input Resistance RIN HI = GND -2 V 300 kI DRIVER LX Withstand Voltage VLX_MAX 60 BST Withstand Voltage VBST_MAX 65 V 740 1100 FA LX Pulldown Current VLX = 2.5V 500 Driver Output Resistance (Sourcing) RON_HP VBST - VLX = 4.5V, 100mA sourcing TA = +25NC 1 1.5 TA = +125NC 1.25 2 Driver Output Resistance (Sinking) RON_HN VBST - VLX = 4.5V, 100mA sinking TA = +25NC 0.75 1 TA = +125NC 1 1.5 2 _______________________________________________________________________________________ V I I High-Side MOSFET Driver for HB LED Drivers and DC-DC Applications (VDD = VBST = 5V, VLX = VGND = 0V, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = TJ = +25°C, unless otherwise noted.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Peak Output Current (Sourcing) IPK_HP VHDRV = 0V 2.5 A Peak Output Current (Sinking) IPK_HN VHDRV = 5V 2.5 A No-load capacitor 1.5 SWITCHING CHARACTERISTICS Rise Time tR Fall Time tF CL = 1000pF 6 CL = 5000pF 18 No-load capacitor 1.5 CL = 1000pF 6 CL = 5000pF 16 ns ns Turn-On Propagation Delay tD_ON Figure 1, CL = 1000pF (Note 3) 11 25 ns Turn-Off Propagation Delay tD_OFF Figure 1, CL = 1000pF (Note 3) 11 25 ns Note 2: All devices are 100% production tested at TA = +25NC. Limits over the operating temperature range are guaranteed by design. Note 3: Guaranteed by design. VIH VIL VHI tD_ON VHDRV 90% tD_OFF 10% tR tF Figure 1. Turn-On/Turn-Off Propagation Delay _______________________________________________________________________________________ 3 MAX15054 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VDD = VBST = 5V, VLX = VGND = 0V, TA = +25°C, unless otherwise noted.) VDD UNDERVOLTAGE LOCKOUT THRESHOLD vs. TEMPERATURE 4.100 4.075 VDD FALLING 3.825 3.800 VDD 1V/div 3.750 3.725 HDRV 1V/div 3.700 3.675 3.650 4.000 3.625 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (NC) BST-LX RISING 3.775 4.025 3.975 BST-LX FALLING 0V 3.600 TEMPERATURE (°C) VDD, BST-LX QUIESCENT SUPPLY CURRENT vs. SUPPLY VOLTAGE MAX15054 toc04 VDD 1V/div HDRV 1V/div QUIESCENT CURRENT (µA) fSW = 5kHz AT HI 0V 40µs/div 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 NO LOAD ON HDRV TA = +25NC IDD TA = -40NC HI INPUT THRESHOLDS vs. TEMPERATURE 3.75 INPUT THRESHOLD (V) 1500 TA = +125NC TA = +85NC 4.00 MAX15054 toc06 2000 IBST 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V) BST OPERATING SUPPLY CURRENT vs. SWITCHING FREQUENCY IBSTO (µA) 400µs/div -40 -25 -10 5 20 35 50 65 80 95 110 125 POWER-UP AND POWER-DOWN SEQUENCE 1750 MAX15054 toc03 fSW = 5kHz AT HI MAX15054 toc05 4.125 4.050 3.850 UVLO THRESHOLD (V) VDD RISING POWER-UP AND POWER-DOWN SEQUENCE 1250 1000 750 500 MAX15054 toc07 4.200 4.150 3.875 MAX15054 toc02 4.225 4.175 BST-LX UNDERVOLTAGE LOCKOUT THRESHOLD vs. TEMPERATURE MAX15054 toc01 4.250 UVLO THRESHOLD (V) MAX15054 High-Side MOSFET Driver for HB LED Drivers and DC-DC Applications 3.50 RISING 3.25 3.00 2.75 2.50 FALLING 2.25 250 2.00 0 0.1 1.0 10 100 1000 SWITCHING FREQUENCY (kHz) 10,000 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (NC) 4 _______________________________________________________________________________________ High-Side MOSFET Driver for HB LED Drivers and DC-DC Applications HDRV OUTPUT HIGH/LOW vs. TEMPERATURE 2MHz OPERATION MAX15054 toc08 HI 2V/div VBST - VHDRV SOURCING 100mA OUTPUT HIGH/LOW (V) 120 0V HDRV 2V/div 100 80 VHDRV - VLX SINKING 100mA 60 40 OUTPUT HIGH = VBST - VHDRV OUTPUT LOW = VHDRV - VLX 20 0V NO LOAD ON HDRV MAX15054 toc09 140 0 200ns/div -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (NC) TURN-ON/TURN-OFF PROPAGATION DELAY vs. TEMPERATURE 96% DUTY CYCLE AT 2MHz MAX15054 toc10 MAX15054 toc11 13.0 12.5 0V 2V/div HDRV 2V/div PROPAGATION DELAY (ns) 2V/div HI 2V/div MAX15054 toc12 4% DUTY CYCLE AT 2MHz 12.0 tD_OFF 11.5 11.0 10.5 tD_ON 10.0 9.5 9.0 0V 8.5 8.0 10ns/div -40 -25 -10 5 20 35 50 65 80 95 110 125 10ns/div TEMPERATURE (°C) TURN-ON AND TURN-OFF PROPAGATION DELAY RISE TIME AND FALL TIME MAX15054 toc13 MAX15054 toc14 HI 2V/div HDRV HI 0V HDRV 1V/div 2V/div 4.7nF CAPACITOR CONNECTED FROM HDRV TO GND, LX = GND 20ns/div HDRV 0V 0V HI 1nF CAPACITOR CONNECTED FROM HDRV TO GND, LX = GND 40ns/div _______________________________________________________________________________________ 5 MAX15054 Typical Operating Characteristics (continued) (VDD = VBST = 5V, VLX = VGND = 0V, TA = +25°C, unless otherwise noted.) MAX15054 High-Side MOSFET Driver for HB LED Drivers and DC-DC Applications Pin Description PIN NAME FUNCTION 1 HI 5V CMOS Logic Input. HI is referenced to GND and is capable of withstanding voltages up to 13.5V for any VDD voltage. 2 GND Ground 3 VDD Input Supply Voltage. Valid supply voltage ranges from 4.6V to 5.5V. Bypass VDD to GND with a 0.1FF ceramic capacitor as close as possible to the device. 4 BST Boost Flying Capacitor Connection. Connect a minimum of a 0.1FF ceramic capacitor between BST and LX for the high-side MOSFET driver supply. Connect a bootstrap Schottky diode between VDD and BST. 5 HDRV 6 LX High-Side Gate-Driver Output. Driver output to drive the high-side external MOSFET gate. Source Connection for High-Side MOSFET. LX also serves as a return terminal for the high-side driver. Functional Diagram BST HIGH-SIDE UVLO D1 EXTERNAL HDRV LX MAX15054 VDD LOW-SIDE UVLO LEVEL SHIFT UP LEVEL SHIFT DOWN HI GND Detailed Description The MAX15054 n-channel MOSFET driver controls an external high-side MOSFET in high-voltage, high-current applications. This driver operates with a supply voltage of 4.6V to 5.5V, and consumes only 300FA of supply current during typical switching operations (fSW = 500kHz) and no-load conditions. The MAX15054 provides 2.5A (typ) sink/source peak current and is capable of operating with large capacitive loads and with switching frequencies up to 2MHz. The device is used to drive the high-side MOSFET without requiring an isolation device such as an optocoupler or a drive transformer. The high-side driver is controlled by a CMOS logic referenced to ground and is powered by a bootstrap circuit formed by an external diode and capacitor. Undervoltage lockout (UVLO) protection is provided for both the high- and low-side driver supplies (BST and VDD) and includes a UVLO hysteresis of 0.2V (typ). The MAX15054’s fast switching times and very short propagation delays (11ns, typ) are ideal for highfrequency applications. Internal logic circuitry prevents shoot-through during output state changes and minimizes package power dissipation. 6 _______________________________________________________________________________________ High-Side MOSFET Driver for HB LED Drivers and DC-DC Applications The high-side driver UVLO threshold (VBST_UVLO) is referenced to LX, and pulls HDRV low when VBST falls below 3.6V (typ) with respect to LX. After the MAX15054 is first energized (VDD > VDD_UVLO), the bootstrap capacitor (CBST) between BST and LX is not charged, and HDRV does not switch since the BST-to-LX voltage is below VBST_UVLO. An internal charging circuit charges the BST-LX supply through an external Schottky diode and within a short time CBST charges through VDD and causes VBST to exceed VBST_UVLO. HDRV then starts switching and follows HI. The hysteresis is 0.2V (typ) for both UVLO thresholds. Output Driver The MAX15054 driver contains low on-resistance p-channel and n-channel devices in a totem pole configuration for the driver output stage. This allows for rapid turn-on and turn-off of high gate-charge (Qg) external switching MOSFETs. The driver exhibits low drain-to-source resistance (RDS(ON)) that decreases for lower operating temperatures. Lower RDS(ON) means higher source and sink currents from the device as the external MOSFET gate capacitance charges and discharges at a quicker rate, resulting in faster switching speeds. The peak source and sink current provided by the driver is 2.5A (typ). Propagation delay from the logic input (HI) to the driver output is 12ns (typ) (Figure 1). The internal driver also contains break-before-make logic to eliminate shootthrough conditions that cause unnecessarily high operating supply currents, efficiency reduction, and voltage spikes at VDD. Bootstrap Diode Connect an external Schottky diode between VDD and BST, in conjunction with an external bootstrap capacitor (CBST), to provide the voltage required to turn on the MOSFET (see the Typical Operating Circuits). The diode charges the bootstrap capacitor from VDD when the high-side switch is off, and isolates VDD when HDRV is pulled high when the driver turns on. Bootstrap Capacitor The bootstrap capacitor (CBST) between BST and LX is used to ensure adequate charge is available to switch the high-side MOSFET. This capacitor is charged from VDD by an external bootstrap diode when the MOSFET is off. The bootstrap capacitor value should be selected carefully to avoid oscillations during turn-on and turnoff at the HDRV output. Choose a capacitor value at least 20 times greater than the total gate capacitance of the MOSFET being switched. Use a low-ESR ceramic capacitor (typically a minimum 0.1FF is needed). The high-side MOSFET’s continuous on-time is limited due to the charge loss from the high-side driver’s quiescent current. The maximum on-time is dependent on the size of CBST, IBST (125FA, max), and VBST_UVLO. Driver Logic Input (HI) The MAX15054 features a 5V CMOS logic input. The required logic-input levels are independent of VDD and are capable of withstanding up to 13.5V. For example, the MAX15054 can be powered by a 5V supply while the logic inputs are provided from 12V logic. Additionally, HI is protected against voltage spikes up to 15V, regardless of the VDD voltage. The logic input has 900mV hysteresis to avoid double pulsing during signal transition. The logic input is a high-impedance input (300kI, typ) and should not be left unconnected to ensure the input logic state is at a known level. With the logic input unconnected, HDRV pulls low as VDD rises above the UVLO threshold. The PWM output from the controller must assume a proper state while powering up the device. Voltage from HDRV to LX is approximately equal to VDD minus the diode drop of the bootstrap diode when in a high state, and zero when in a low state. _______________________________________________________________________________________ 7 MAX15054 Undervoltage Lockout The MAX15054 drives an external high-side MOSFET. Both the high- and low-side supplies feature separate UVLO protection that monitors each driver’s input supply voltage (BST-LX and VDD). The low-side supply UVLO threshold (VDD_UVLO) is referenced to GND and pulls the driver output low when VDD falls below 4V (typ) irrespective of the high-side UVLO condition. High-Side MOSFET Driver for HB LED Drivers and DC-DC Applications MAX15054 Typical Operating Circuits (continued) VIN D1 VCC VDD BST C1 CBST GND MAX15054 HDRV Q1 LX D3 L HI D2 R11 COUT Q2 C7 IN NDRV R9 C6 CS R12 R10 C2 R1 EN C3 OVP R2 OUT1 VCC C4 OUT4 VCC R3 MAX16814 C5 ISET R9 VDRV DIM LEDGND FLAG R5 R6 RSDT R7 CC COMP RC RT R8 SGND PGND 8 _______________________________________________________________________________________ High-Side MOSFET Driver for HB LED Drivers and DC-DC Applications ___Chip Information PROCESS: BiCMOS TOP VIEW HI 1 GND 2 + MAX15054 VDD 3 6 LX 5 HDRV 4 BST Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 6 SOT23 U6+1 21-0058 SOT23 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2009 Maxim Integrated Products 9 Maxim is a registered trademark of Maxim Integrated Products, Inc. MAX15054 Pin Configuration