Renesas ISL8510IRZ-T

Overview

ISL8510IRZ-T from Renesas (formerly Intersil) is a dual-output power management IC integrating a 1A synchronous buck PWM controller with internal N-channel MOSFET and a 500mA adjustable LDO regulator. It delivers regulated outputs of 0.6–20V (PWM) and 0.6–4.2V (LDO), operates from 5.5–25V input or fixed 5V ±10%, and switches at 500kHz for compact point-of-load designs in FPGA and wireless chipset power rails.

For engineers reviewing the ISL8510IRZ-T datasheet, ISL8510IRZ-T pinout, ISL8510IRZ-T application, or ISL8510IRZ-T equivalent, key selection considerations include independent enable control (EN_PWM/EN_LDO), dual PGOOD signals (PG_PWM/PG_LDO), externally adjustable soft-start, voltage-mode control with feed-forward, and thermal/overcurrent/undervoltage protection for robust system-level power sequencing.

Technical Context

The ISL8510IRZ-T implements two independent regulation paths: a voltage-mode buck controller using input-voltage feed-forward to reject line variation and simplify loop compensation, and an LDO regulator with internal PMOS pass devices and adjustable output via FB_LDO feedback. Both regulators feature dedicated fault monitors - the buck uses r_DS(ON)-based current sensing with 2.7A typical OCP threshold and latch-off UVLO at 70% V_OUT, while the LDO employs current-limit shutdown at 800mA typical with no UV/OV protection.

Power sequencing is managed through separate enable inputs (EN_PWM, EN_LDO), POR thresholds (4.4V rising on VCC, 1.2V on VIN_LDO), and soft-start initiated by a 30µA current source charging an external capacitor on SS pin. The integrated 5V VCC LDO powers all internal logic and requires decoupling; when supplied from 5V ±10%, VIN and VCC must be shorted per Table 1.

Key Specifications

Pinout & Package

ISL8510IRZ-T is housed in a thermally enhanced 24-lead 4mm × 4mm QFN package with exposed thermal pad (Pb-free, RoHS compliant). The pad must be soldered to a GND plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output power management applications.

Compared with TPS65270RGET and MAX16922ATG+, the ISL8510IRZ-T offers unique independent enable/control of both regulators and dual open-drain PGOOD outputs - essential for precise power sequencing in FPGA and wireless baseband systems where rail timing and fault isolation are critical.

Availability

ISL8510IRZ-T is available at Aetrix Electronics and suitable for FPGA power delivery, wireless baseband processor supplies, hand-held instrument power rails, and WLAN PCMCIA card designs requiring stable component supply and long-term production continuity.

Supply support for ISL8510IRZ-T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Renesas Electronics acquired Intersil in 2017 and maintains full product support, documentation, and manufacturing continuity for the ISL8510IRZ-T.

The ISL8510IRZ-T belongs to Renesas' legacy high-performance power management portfolio, designed specifically for compact, dual-rail point-of-load applications in communications, computing, and portable instrumentation.

FAQ

What input voltage configurations does the ISL8510IRZ-T support?

The ISL8510IRZ-T supports two distinct input modes: a variable 5.5V–25V supply connected only to VIN (with internal 5V VCC LDO active), or a fixed 5V ±10% supply applied to both VIN and VCC pins (bypassing the internal LDO). The latter configuration requires tying VIN and VCC together and still mandates a 1µF ceramic decoupling capacitor on VCC.

How is output voltage programmed on the ISL8510IRZ-T buck and LDO regulators?

The ISL8510IRZ-T uses resistor dividers to scale output voltage against its internal 0.6V reference. For the buck regulator, FB_PWM connects to the divider midpoint (V_OUT = 0.6·(1+R1/R2)); for the LDO, FB_LDO performs the same function (V_OUT = 0.6·(1+R5/R6)). The datasheet specifies minimum divider current (200nA for LDO, no minimum for buck) and recommends R1/R5 values between 1kΩ and 10kΩ for optimal noise immunity.

Does the ISL8510IRZ-T require an external Schottky diode, and why?

Yes - the ISL8510IRZ-T requires an external Schottky diode connected from PHASE to VOUT. Because it integrates only the high-side N-channel MOSFET (not synchronous rectification), the diode provides the return current path during the switch-off period. A Schottky diode is specified to minimize forward voltage drop and conduction losses, directly improving efficiency - especially at light loads and high duty cycles.

What protection features are integrated into the ISL8510IRZ-T?

The ISL8510IRZ-T integrates overcurrent protection (2.7A typical for buck, 800mA typical for LDO), thermal shutdown (150°C with 15°C hysteresis), undervoltage lockout (70% V_OUT for buck), and power-on reset (4.4V rising threshold on VCC). It does not include overvoltage protection for either regulator, nor does the LDO feature undervoltage protection - those functions must be implemented externally if required.

Can the ISL8510IRZ-T generate a 5.0V output from a 12V input, and what design considerations apply?

Yes - the ISL8510IRZ-T buck regulator supports 0.6V–20V output, so 5.0V is fully within range. Key considerations include selecting R1/R2 to set V_FB = 0.6V (e.g., R1 = 10kΩ, R2 = 1.36kΩ), ensuring the external Schottky diode and 10µH inductor are rated for 1A DC and peak currents, and verifying thermal performance: at 12V→5V/1A, power dissipation is ~1.5W - requiring adequate copper area on the exposed pad and ambient temperature ≤+70°C for reliable operation.