EVALUATION KIT AVAILABLE Click here for production status of specific part numbers. MAX258 500mA, Push-Pull Transformer Driver for Isolated Power Supplies General Description Features and Benefits The MAX258 is a 500mA, push-pull transformer driver Simple, Flexible Design designed to provide a simple solution for isolated power +3.0V to +5.5V Supply Range supplies. The IC has an internal oscillator and operates Low R 300m (max) at 4.5V ON from a single +3.0V to +5.5V supply. The transformers Up to 90% Efficiency secondary-to-primary winding ratio defines the output Provides Up to 500mA to the Transformer voltage, allowing selection of virtually any isolated output 250kHz or 600kHz Internal Oscillator Frequency voltage with galvanic isolation. -40C to +125C Temperature Range The device features an integrated oscillator driving a pair Integrated System Protection of n-channel power switches. Internal circuitry guarantees Undervoltage Lockout a fixed 50% duty cycle to prevent DC current flow through Thermal Shutdown the transformer. Saves Space on Board The IC operates with up to 500mA of continuous current Small 8-Pin TDFN Package (2mm x 3mm) and features undervoltage lockout and thermal shutdown. Applications The IC includes a low-current shutdown mode to reduce the overall supply current to less than 5A (max) when the Power Meter Data Interface driver is disabled. Isolated Fieldbus Interface Medical Equipment The MAX258 is available in a small 8-pin (2mm x 3mm) Isolated Analog Front-End TDFN package and is specified over the -40C to +125C temperature range. Ordering Information appears at end of data sheet. Typical Operating Circuit 5V 1F V DD T2 HICLK 1CT:1.3CT ISOLATED 1F V OUT MAX258 10F EN T1 GND PGND 19-6696 Rev 1 9/18MAX258 500mA, Push-Pull Transformer Driver for Isolated Power Supplies Absolute Maximum Ratings (All voltages referenced to GND.) Operating Temperature Range ..........................-40C to +125C V , HICLK, EN ......................................................-0.3V to +6V Junction Temperature ......................................................+150C DD T1, T2 .................................................................-0.3V to +16.5V Storage Temperature Range .............................-65C to +150C T1, T2 Maximum Continuous Current ..............................+1.75A Lead Temperature (soldering, 10s) .................................+300C Continuous Power Dissipation (T = +70C) Soldering Temperature (reflow) .......................................+260C A TDFN (Multilayer Board) (derate 16.7mW/C above +70C) ..........................1333.3mW 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 PACKAGE TYPE: 8 TDFN Package Code T823+1 Outline Number 21-0174 Land Pattern Number 90-0091 THERMAL RESISTANCE, FOUR-LAYER BOARD Junction to Ambient ( ) 60C/W JA Junction to Case ( ) 11C/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. Electrical Characteristics (V = +3.0V to 5.5V, T = T to T , unless otherwise noted. Typical values at V = +5.0V and T = +25C.) (Note 1) DD A MIN MAX DD A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC CHARACTERISTICS Supply Voltage Range V 3.0 5.5 V DD V = 0V 1.1 1.8 HICLK V = 0V, T1 and T2 not EN Supply Current I mA DD connected V = V 2.1 3.5 HICLK DD V = V , T1, T2, HICLK connected to GND EN DD Disable Supply Current I 5 A DIS or V (Note 3) DD V = 3.0V 160 350 DD Driver Output Resistance R I = 500mA m O OUT V = 4.5V 145 300 DD Undervoltage Lockout V V rising 2.6 2.75 2.9 V UVLO DD Threshold Undervoltage Lockout V 250 mV UVLO HYST Threshold Hysteresis T1, T2 Leakage Current I V = V , T1, T2 = 0V or V -1 +1 A LKG EN DD DD Maxim Integrated 2 www.maximintegrated.com