DATASHEET ISL78201 FN8615 Rev 2.00 40V 2.5A Regulator with Integrated High-Side MOSFET for Synchronous Buck or August 15, 2016 Boost Buck Converter The ISL78201 is an AEC-Q100 qualified 40V, 2.5A synchronous Features buck or boost buck controller with a high-side MOSFET and Buck mode: input voltage range 3V to 40V (refer to Input low-side driver integrated. In Buck mode, the ISL78201 Voltage on page 14 for more details) supports a wide input range of 3V to 40V. In Boost-Buck mode, the input range can be extended down to 2.5V and output Boost mode expands operating input voltage lower than regulation can be maintained when V drops below V , IN OUT 2.5V (refer to Input Voltage on page 14 for more details) enabling sensitive electronics to remain on during Selectable forced PWM mode or PFM mode cold-cranking and start-stop applications. 300A IC quiescent current (PFM, no load) 180A input The ISL78201 has a flexible selection of operation modes quiescent current (PFM, no load, V tied to AUXVCC) OUT including forced PWM mode and an optional switch to PFM Less than 5A (MAX) shutdown input current (IC disabled) mode for light loads. In PFM mode, the quiescent input current is as low as 300A and can be further reduced to 180A with Operational topologies AUXVCC connected to V under 12V V and 5V V OUT IN OUT -Synchronous buck application. The load boundary between PFM and PWM can be -Non-synchronous buck programmed to cover wide applications. - Two-stage boost buck The low-side driver can be either used to drive an external - Noninverting single inductor buck boost low-side MOSFET for a synchronous buck, or left unused for a Programmable frequency from 200kHz to 2.2MHz and standard non-synchronous buck. The low-side driver can also frequency synchronization capability be used to drive a boost converter as a preregulator that greatly expands the operating input voltage range down to 1% Tight voltage regulation accuracy 2.5V or lower (refer to Typical Application Schematic III - Boost Reliable cycle-by-cycle overcurrent protection Buck Converters on page 5). - Temperature compensated current sense The ISL78201 offers the most robust current protections. It - Programmable OC limit uses peak current mode control with cycle-by-cycle current - Frequency foldback and hiccup mode protection limiting. It is implemented with frequency foldback undercurrent limit condition in addition, the hiccup 20 Ld HTSSOP package overcurrent mode is also implemented to guarantee reliable AEC-Q100 qualified operations under harsh short conditions. The ISL78201 has Pb-free (RoHS compliant) comprehensive protections against various faults including overvoltage and over-temperature protections, etc. Applications Automotive applications General purpose power regulator 24V Bus power Battery power Embedded processor and I/O supplies 100 PGOOD 95 6V V IN EN V VIN IN 90 MODE 12V V 85 IN SYNC BOOT AUXVCC 80 40V V VCC V OUT IN ISL78201 75 PHASE 24V V ILIMIT IN 70 LGATE SS 65 PGND 60 EXT BOOST FB FS 55 SGND COMP 50 0.1m 1m 10m 100m 1 2.5 LOAD CURRENT (A) FIGURE 1. TYPICAL APPLICATION FIGURE 2. EFFICIENCY, SYNCHRONOUS BUCK, PFM MODE, V 5V, T = +25C OUT A FN8615 Rev 2.00 Page 1 of 23 August 15, 2016 EFFICIENCY (%)ISL78201 Pin Configuration ISL78201 (20 LD HTSSOP) TOP VIEW PGND 1 20 LGATE SYNC BOOT 2 19 VIN 3 18 EXT BOOST VIN 4 17 PHASE SGND 5 21 16 PHASE PAD VCC 6 15 PGOOD AUXVCC 7 14 MODE EN 8 13 ILIMIT FS 9 COMP 12 SS 10 11 FB Functional Pin Description PIN NAME PIN DESCRIPTION PGND 1 This pin is used as the ground connection of the power flow including driver. BOOT 2 This pin provides bias voltage to the high-side MOSFET driver. A bootstrap circuit is used to create a voltage suitable to drive the internal N-channel MOSFET. The boot charge circuitries are integrated inside the IC. No external boot diode is needed. A 1F ceramic capacitor is recommended to be used between BOOT and PHASE pin. VIN 3, 4 Connect the input rail to these pins that are connected to the drain of the integrated high-side MOSFET, as well as the source for the internal linear regulator that provides the bias of the IC. Range: 3V to 40V. With the part switching, the operating input voltage applied to the VIN pins must be under 40V. This recommendation allows for short voltage ringing spikes (within a couple of ns time range) due to switching while not exceeding absolute maximum ratings. SGND 5 This pin provides the return path for the control and monitor portions of the IC. VCC 6 This pin is the output of the internal linear regulator that supplies the bias for the IC including the driver. A minimum 4.7F decoupling ceramic capacitor is recommended between VCC to ground. AUXVCC 7 This pin is the input of the auxiliary internal linear regulator, which can be supplied by the regulator output after power- up. With such a configuration, the power dissipation inside the IC is reduced. The input range for this LDO is 3V to 20V. In Boost mode operation, this pin works as boost output overvoltage detection pin. It detects the boost output through a resistor divider. When the voltage on this pin is above 0.8V, the boost PWM is disabled and when voltage on this pin is below 0.8V minus the hysteresis, the boost PWM is enabled. Range: 3V to 20V. EN 8 The controller is enabled when this pin is pulled HIGH or left floating. The IC is disabled when this pin is pulled LOW. Range: 0V to 5.5V. FS 9 To connect this pin to VCC, or GND, or left open will force the IC to have 500kHz switching frequency. The oscillator switching frequency can also be programmed by adjusting the resistor from this pin to GND. SS 10 Connect a capacitor from this pin to ground. This capacitor, along with an internal 5A current source, sets the soft-start interval of the converter. Also this pin can be used to track a ramp on this pin. FB 11 This pin is the inverting input of the voltage feedback error amplifier. With a properly selected resistor divider connected from VOUT to FB, the output voltage can be set to any voltage between the input rail (reduced by maximum duty cycle and voltage drop) and the 0.8V reference. Loop compensation is achieved by connecting an RC network across COMP and FB. The FB pin is also monitored for overvoltage events. COMP 12 Output of the voltage feedback error amplifier. ILIMIT 13 Programmable current limit pin. With this pin connected to the VCC pin, or to GND, or left open, the current limit threshold is set to default 3.6A the current limit threshold can be programmed with a resistor from this pin to GND. MODE 14 Mode selection pin. Pull this pin to GND for forced PWM mode to have it floating or connected to VCC will enable PFM mode when the peak inductor current is below the default threshold of 700mA. The current boundary threshold between PFM and PWM can also be programmed with a resistor at this pin to ground. For more details on PFM mode operation refer to the Functional Description on page 13. FN8615 Rev 2.00 Page 2 of 23 August 15, 2016