Renesas ISL59420IU

Overview

ISL59420IU from Intersil is a 420MHz bandwidth, 2:1 video multiplexing amplifier with user-selectable gain (AV = 1 or 2), high-speed three-state output (HIZ), and low-power shutdown mode consuming only 5mW. It features 966V/µs slew rate at AV = 1 and operates across –40°C to +85°C for HDTV analog inputs and broadcast video routing.

For engineers reviewing the ISL59420IU datasheet, ISL59420IU pinout, ISL59420IU application, or ISL59420IU equivalent, this page delivers verified electrical specs, functional truth table, package-validated pin roles, real-world video switching use cases, and two confirmed alternative parts with documented technical and application differences.

Technical Context

The ISL59420IU implements a current-feedback amplifier architecture optimized for video signal routing, supporting dual-gain configurations via external RF/RG resistor networks (e.g., 200Ω for AV = 1, 453Ω for AV = 2). Its channel select logic uses binary S0 input with ENABLE and HIZ pins enabling independent power-down and output disable control.

It integrates internal pull-down resistors on all logic inputs (S0, ENABLE, HIZ), allowing floating operation while maintaining defined states. The inverting input (IN-) is sensitive to stray capacitance (optimized for 0.4–0.7pF), and output performance is tuned for 1–6pF total load capacitance (CL) with 500Ω termination.

Key Specifications

Pinout & Package

ISL59420IU is housed in a Pb-free 10-lead MSOP (M10.118A) package with 0.5mm pitch, 3.0mm × 4.9mm body, and exposed thermal pad (not electrically connected). Pin 1 marked with dot; pin numbering counterclockwise from top-left.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar video multiplexing amplifier applications.

Compared with AD8170ARZ and THS7374IPW, the ISL59420IU uniquely combines 420MHz bandwidth, integrated S0/ENABLE/HIZ logic, and 5mW shutdown-enabling compact, low-power, bus-shared HD video switchers without external support circuitry.

Availability

ISL59420IU is available at Aetrix Electronics and suitable for HDTV/DTV analog inputs, video projectors, and security video systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ISL59420IU 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

Intersil Corporation designs high-performance analog semiconductors for flat-panel displays, mobile devices, and industrial systems, operating under ISO9001 quality standards.

The ISL59420IU belongs to Intersil's high-speed video amplifier product line, engineered specifically for broadcast-grade analog video routing, matrix switching, and HD signal conditioning with minimal distortion.

FAQ

What is the maximum recommended supply voltage for ISL59420IU?

The absolute maximum supply voltage (V+ to V−) for ISL59420IU is 11V. Operation at ±5V (10V total) is standard; exceeding ±5.5V risks permanent damage per Absolute Maximum Ratings. The internal dV/dt clamp enforces a 1V/µs supply turn-on slew rate-exceeding this during hot-plug can cause destructive current flow through ESD diodes. Always apply V− before V+ and use Schottky clamps (e.g., MBR0550T) if sequencing cannot be guaranteed.

How does the ISL59420IU achieve 420MHz bandwidth at AV = 1 but only 165MHz at AV = 2?

The ISL59420IU uses a current-feedback amplifier topology where bandwidth is inversely proportional to closed-loop gain. At AV = 1 (RF = RG = 200Ω), the feedback network minimizes phase lag, enabling 420MHz (–3dB). At AV = 2 (RF = RG = 453Ω), increased loop gain reduces stability margin, lowering bandwidth to 165MHz. This trade-off is inherent to CFA design and validated in Figures 2–5 of the FN7459 datasheet-no external compensation is required.

Can ISL59420IU drive a 75Ω video load directly?

No, ISL59420IU is optimized for 500Ω loads (per datasheet test conditions), not 75Ω. Driving 75Ω directly degrades bandwidth, increases distortion, and risks instability due to excessive feedback loop gain. For 75Ω systems, use Figure 25A's backloaded configuration with series 475Ω/462.5Ω termination at the source, or add external 425Ω series resistor at OUT to match 75Ω while preserving 500Ω internal load condition.

What is the purpose of the IN− pin on ISL59420IU, and why is its layout critical?

The IN− pin is the inverting input of the output amplifier, forming the feedback node with external RF/RG resistors. Stray capacitance here (especially CG to ground) directly impacts stability-datasheet specifies 0.4–0.7pF as optimal. Layout errors (e.g., long traces, parallel routing with OUT) increase CG beyond 1pF, causing gain peaking, overshoot, or oscillation. Place RF/RG resistors within 1/4 inch of IN−, use 0603 or smaller packages, and avoid vias near this pin.

Does ISL59420IU require external power supply decoupling capacitors?

Yes, ISL59420IU requires at least two decoupling capacitors: 1000pF and 0.01µF, placed as close as possible to the V+ and V− pins with no vias in the path. High-frequency noise on supplies degrades PSRR (–68dB typical) and introduces glitches on OUT. The 1000pF capacitor suppresses UHF noise (>100MHz), while 0.01µF handles mid-band ripple. Larger bulk capacitors (e.g., 10µF) may be added farther away, but proximity to the IC is essential for 420MHz operation.