EVALUATION KIT AVAILABLE Click here for production status of specific part numbers. MAX25601A/ Synchronous Boost and MAX25601B Synchronous Buck LED Controllers General Description Benefits and Features The MAX25601A/B is a synchronous boost controller fol- Integration Minimizes BOM for High-Brightness LED lowed by a synchronous buck LED controller. The 4.5V to Driver, Saving Space and Cost 40V input voltage range of the boost controller is ideal for Wide Input-Voltage Range from 4.5V to 40V automotive applications, and acts as a pre-boost power Wide Boost-Output Range up to 65V supply for the second-stage buck LED controller. Programmable Switching Frequency Optimizes Component Size The synchronous boost is a current-mode controller External MOSFETs Can be Sized for Appropriate that can be be paralleled with another device to provide Current higher output power. A SYNCOUT pin provides the clock Synchronous Rectification Provides High Efficiency to drive the RT/SYNCIN pin of the other device, enabling and Fast Transient Response two-phase 180-degree out-of-phase operation. The boost Average Current-Mode Control for Buck Eliminates converter can be programmed with a switching frequency Compensation Components of 200kHz to 2.2MHz. Spread spectrum is included to Wide Dimming Ratio Allows High Contrast Ratio reduce EMI. An internal digital soft-start feature is pro- Analog Dimming and PWM Dimming vided to enable a smooth power up of the boost output. Analog Voltage-Controlled PWM Dimming Protection features like hiccup mode, overvoltage protec- tion, and thermal shutdown are provided. Protection Features and Wide Temperature Range 3 Increase System Reliability The synchronous buck LED controller uses Maxim s F Short Circuit, Overvoltage, and Thermal Protection Architecture, a proprietary average-current-mode control -40C to +125C Operating Temperature Range scheme to regulate the inductor current at a constant switching frequency without any control-loop compensa- Simplified Application Circuit tion. Inductor current is sensed in the bottom synchronous n-channel MOSFET. The device operates over a wide L BOOST R BOOST IN INPUT 4.5V to 65V input range at switching frequencies as high V OUT N1 as 1MHz. Both analog and PWM dimming are included. C IN CBOOST LED current can be monitored on the IOUTV pin. INP INN DH1 INPUT AND BIAS Both controllers have high- and low-side gate drivers LX1 with at least 1A peak source and sink-current capabil- SYNC IN/OUT N2 DL1 ity. Adaptive non-overlap control logic prevents shoot- BOOST FLTB, IOUTV VOUT through currents during transition. Both the boost and the MAX25601 OUT, FB buck faults are monitored on the FLT pin. N3 DH2 BUCK PWM, ANALOG The MAX25601A is available in a 32-pin SWTQFN pack- L BUCK VOUT DIMMING LX2 age and the MAX25601B is available in a 28-pin TSSOP BUCK TON C BUCK package. The 32-pin package features an additional DL2 N4 SETTING switch control that can be used in high-beam/low-beam COMP CSP BUCK C COMP and heads-up display applications. R CS LED VOUT R COMP CSN Applications SHUNT DRV* Automotive Exterior Lighting: High-Beam/Low-Beam/ Signal/Position Lights, Daytime Running Lights PWM HUD SHUNT CTRL* (DRLs), Matrix Light, Pixel Light, and Other Adaptive N5 * MAX25601A ONLY Front-Light Assemblies Commercial, Industrial, and Architectural Lighting Ordering Information appears at end of data sheet. 19-100564 Rev 1 7/19MAX25601A/ Synchronous Boost and MAX25601B Synchronous Buck LED Controllers Absolute Maximum Ratings IN, UVEN, INP, INN to AGND................................-0.3V to +40V PGND to AGND ....................................................-0.3V to +0.3V LX1, TON to PGND ...............................................-0.3V to +70V Continous Power Dissipation (Single-Layer Board), LX2 to PGND............................................................-1V to +70V 32 pin SW TQFN T3255Y+6C BST to LX ............................................................-0.3V to +6V (T = +70C, derate 21.3mW/C above +70C.) .......1702mW A DH to LX ............................................... -0.3V to V +0.3V Continuous Power Dissipation (Multilayer Board), BST DL , SHUNT DRV to PGND ......................-0.3V to V +0.3V 32 pin SW TQFN T3255Y+6C DRV CSP, CSN to PGND ................................................-2.5V to +6V (T = +70C, derate 34.5mW/C above +70C.) .......2759mW A CSP to CSN, INP to INN ......................................-0.3V to +0.3V Continuous Power Dissipation (Single-Layer Board), V to SGND ..............................................-0.3V to V +0.3V 28 pin TSSOP U28E+1C CC DRV REFI, IOUTV, SYNCOUT to AGND.............-0.3V to V +0.3V (T = +70C, derate 22.2mW/C above +70C.) .......1777mW DRV A FB, OUT, COMP to AGND ..........................-0.3V to V +0.3V Continuous Power Dissipation (Multilayer Board), DRV FLT, SHUNT CTRL, PWMDIM, 28 pin TSSOP U28E+1C (T = +70C, A RT/SYNCIN to AGND ..........................................-0.3V to +6V derate 29.7mW/C above +70C.) .................mW to 2380mW VDRV to PGND ......................................................-0.3V to +6V Operating Temperature Range ............................-40C to 125C 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. Package Information 32 pin TQFN Package Code T3255Y+6C Outline Number 21-100041 Land Pattern Number 90-100066 Thermal Resistance, Single-Layer Board: Junction to Ambient ( ) 47C/W JA Junction to Case ( ) 3C/W JC Thermal Resistance, Four-Layer Board: Junction to Ambient ( ) 36C/W JA Junction to Case ( ) 3C/W JC 28 pin TSSOP Package Code U28E+1C Outline Number 21-100182 Land Pattern Number 90-100069 Thermal Resistance, Single-Layer Board: Junction to Ambient ( ) 45C/W JA Junction to Case ( ) 2C/W JC Thermal Resistance, Four-Layer Board: Junction to Ambient ( ) 33.6C/W JA Junction to Case ( ) 3.3C/W JC For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a +, , or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. Maxim Integrated 2 www.maximintegrated.com