ISL97901CRZ-T7A - 4-Ch RGB LED Driver, 1.5A, Buck-Boost | Renesas
MPN: ISL97901CRZ-T7A ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.77 | $5.77 |
| 10 | $5.19 | $51.90 |
| 100 | $4.62 | $462.00 |
| 500 | $4.18 | $2,090.00 |
| 1,000 | $3.73 | $3,730.00 |
| 2,500 | $3.31 | $8,275.00 |
ISL97901CRZ-T7A Overview
A LED driver is a power-management IC that converts a battery or bus voltage into precisely controlled DC current for one or more light-emitting diodes. Within the broader power-management hierarchy, a constant-current LED driver sits beside voltage regulators, battery chargers, and supervisors, and is itself a sub-class of DC-DC converters (step-down/step-up). White LEDs require current-mode regulation (not voltage-mode) because their luminance is proportional to forward current; the ISL97901CRZ-T7A therefore implements independent current sinks per channel rather than voltage references.
Key features include independent PWM and analog dimming on every channel, an I2C-compatible interface for color mixing and brightness control, automatic white-balance calibration to compensate for RGB LED binning variance, and 1.5 A peak channel current with a low 100 mV typical current-sense voltage drop. The device also integrates thermal shutdown, soft-start, fault reporting (open/short LED detection), and a hardware EN pin for power sequencing. Its QFN-28 4x5 mm exposed-pad package yields a thermal resistance of approximately 33 C/W, enabling continuous operation across -40 C to +85 C without external heatsinking at typical cell-phone backlight loads.
Architecturally, the ISL97901CRZ-T7A pairs a synchronous buck-boost converter with four linear current sinks. The converter maintains V_LED at the minimum headroom required above the highest VF LED string, while the current sinks regulate each channel independently. Automatic white-balance uses an onboard optical-feedback or factory-calibrated trim routine so that equal PWM duty yields perceived equal luminance across red, green, and blue LEDs despite part-to-part color-bin spread.
Typical applications include smartphone and tablet LCD backlighting, RGB status indicators in wearables, AR/VR headset illumination, and small-format RGB-LED matrix panels. When designing with this part, place the input ceramic bypass capacitor within 2 mm of the VIN pin and keep the boost inductor loop area minimal to limit EMI; the I2C lines should be pulled up to VIO (typically 1.8 V) rather than VIN to match modern application-processor I/O domains.
Drop-in alternatives for ISL97901CRZ-T7A — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ISL97901CRZ-T7A (same form factor and footprint) — differing in Automatic White Balance, Color Sequencing, Per-Channel Current, Topology.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ISL97901CRZ-T
✅ Drop-In📋 Reference alternative (not in catalog)
ISL97901CRZ-TK
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →ISL97901CRZ
✅ Drop-In📋 Reference alternative (not in catalog)
ISL97901CRZ-T7A Maximum Ratings & Electrical Characteristics
| Topology | Buck-Boost (Step-Down + Step-Up) |
| Number of LED Outputs | 4 (RGB + W or 4 independent) |
| Per-Channel Current | Up to 1.5 A (sequential) |
| Total Dimming Current | 375 mA per channel (DC) |
| Input Voltage Range | 2.7 V to 5.5 V |
| Battery Support | Single-cell Li-ion |
| Output Channels | 4 x DC-DC constant-current sinks |
| Dimming Control | I2C + PWM + Analog |
| Color Sequencing | Yes (built-in) |
| Automatic White Balance | Yes (built-in) |
| Package | 28-QFN (4x5 mm) with exposed pad |
| Operating Temperature | -40 C to +85 C |
| Fault Detection | Open LED, Short LED, Thermal Shutdown |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
ISL97901CRZ-T7A Pin Configuration
| Pin 1 | LED1 — Current sink for LED string 1 |
| Pin 2 | LED2 — Current sink for LED string 2 |
| Pin 3 | LED3 — Current sink for LED string 3 |
| Pin 4 | LED4 — Current sink for LED string 4 |
| Pin 5 | GND — Ground |
| Pin 6 | VIN — Input supply (2.7 V to 5.5 V) |
| Pin 7 | EN — Hardware enable (active high) |
| Pin 8 | SDA — I2C data |
| Pin 9 | SCL — I2C clock |
| Pin 10 | ADDR — I2C address select |
| Pin 11 | PWM — PWM dimming input |
| Pin 12 | FLT — Fault output (open-drain) |
| Pin 13 | TEST — Factory test pin (NC in application) |
| Pin 14 | VIO — Digital I/O supply (1.8 V typical) |
| Pin 15 | NC — Not connected (per datasheet) |
| Pin 16 | NC — Not connected (per datasheet) |
| Pin 17 | SW — Buck-boost switch node |
| Pin 18 | LX1 — Inductor node 1 |
| Pin 19 | LX2 — Inductor node 2 |
| Pin 20 | BST — Bootstrap capacitor for high-side driver |
| Pin 21 | VOUT — Buck-boost regulated output |
| Pin 22 | FB — Output voltage feedback |
| Pin 23 | COMP — Compensation network node |
| Pin 24 | AGND — Analog ground |
| Pin 25 | REF — Internal reference bypass |
| Pin 26 | ISET — Current set resistor |
| Pin 27 | NC — Not connected (per datasheet) |
| Pin 28 | NC — Not connected (per datasheet) |
Typical Applications
ISL97901CRZ-T7A is suitable for 6 applications: Smartphone LCD Backlight, Tablet and Notebook Display Backlight, Wearable RGB Status Indicators, AR/VR Headset Illumination, RGB LED Matrix Panels (Small Format), Industrial Portable Diagnostic Equipment.
Smartphone LCD Backlight
The ISL97901CRZ-T7A fits smartphone LCD backlighting because it operates directly from a single-cell Li-ion battery (2.7 V to 5.5 V) and integrates a buck-boost converter that maintains proper LED forward voltage as the battery discharges from 4.2 V to 3.0 V. Its 1.5 A peak sequential current capability lets a single IC drive a four-string white-LED backlight bar at full brightness (typically 20 mA to 30 mA per string). The 28-QFN 4x5 mm footprint fits within the tight Z-height and area constraints of a phone main board, and the I2C interface ties directly into the application processor for ambient-light-driven brightness control.
Recommended
Tablet and Notebook Display Backlight
The ISL97901CRZ-T7A suits larger tablet and notebook display backlights because its 1.5 A peak sequential drive and 375 mA continuous current can be paralleled across multiple LED strings for higher luminance output. The integrated buck-boost ensures uniform brightness across the full battery or USB-PD input range (2.7 V to 5.5 V), avoiding the visible dimming that occurs with buck-only drivers as the supply drops. Built-in automatic white balance compensates for white-LED bin variance, eliminating panel-level calibration labor and reducing BOM cost in mass production.
Recommended
Wearable RGB Status Indicators
The ISL97901CRZ-T7A is a strong fit for wearable devices such as smartwatches, fitness bands, and hearables that need RGB status indication. Its 2.7 V to 5.5 V input accepts a small Li-ion or Li-polymer cell directly, while the four-channel architecture lets one IC drive red, green, blue, and amber indicators from a single device. The I2C + PWM + analog dimming allows the host MCU to mix colors and modulate brightness for notification alerts. The 28-QFN 4x5 mm footprint with exposed pad yields adequate thermal dissipation for the short, low-duty current bursts typical of indicator duty cycles.
Recommended
AR/VR Headset Illumination
The ISL97901CRZ-T7A fits AR/VR headset illumination because it can drive high-brightness RGB LEDs for inside-out tracking markers, eye-tracking illumination, or peripheral indicator lighting. Its sequential 1.5 A peak channel capability supports the high pulse currents that high-brightness LEDs require to reach the luminance needed for camera-based tracking at low duty cycles. The buck-boost architecture tolerates the wide input voltage swings that occur when the headset draws heavy compute load current from the same battery, preventing backlight dropout during peak GPU activity.
Recommended
RGB LED Matrix Panels (Small Format)
The ISL97901CRZ-T7A suits small-format RGB LED matrix panels used in signage, indicator walls, or decorative lighting because its four-channel architecture and I2C control support cascaded multi-IC designs via address select. Built-in color sequencing reduces the host MCU's real-time PWM overhead, freeing processing capacity for higher-level effects. The integrated fault detection (open LED, short LED, thermal shutdown) improves field reliability by automatically disabling failed strings rather than drawing excessive current through a shorted chain.
Recommended
Industrial Portable Diagnostic Equipment
The ISL97901CRZ-T7A fits portable industrial diagnostic tools such as handheld oscilloscope displays, spectrum analyzer screens, and field-test instruments where reliable, calibrated backlight brightness is required across temperature extremes. Its -40 C to +85 C operating range and automatic white-balance calibration ensure consistent luminance from cold-start to hot operating conditions. The buck-boost topology accepts a wide variety of input sources - Li-ion packs, USB-PD, or regulated 5 V rails - simplifying the power tree for handheld test equipment designs.
Recommended
Recommended Products Summary
Engineering reference data for ISL97901CRZ-T7A — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ISL97901CRZ-T | ISL97901CRZ-TK | ISL97901CRZ |
|---|---|---|---|---|
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics |
| Package | 28-QFN (4x5 mm) | 28-QFN (4x5 mm) - same | 28-QFN (4x5 mm) - same | 28-QFN (4x5 mm) - same |
| Number of LED Channels | 4 | 4 | 4 | 4 |
| Peak Channel Current | 1.5 A | 1.5 A | 1.5 A | 1.5 A |
| Continuous Dimming Current | 375 mA | 375 mA | 375 mA | 375 mA |
| Input Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| Topology | Buck-Boost | Buck-Boost | Buck-Boost | Buck-Boost |
| Dimming Interface | I2C + PWM + Analog | I2C + PWM + Analog | I2C + PWM + Analog | I2C + PWM + Analog |
| Color Sequencing + Auto White Balance | Yes | Yes | Yes | Yes |
| Reel Pack Format | Tape & Reel (T7A suffix) | Tape & Reel (T suffix, 1000 pcs) | Tape & Reel (TK suffix) | Tray |
Key Differentiators
- Integrated automatic white-balance calibration (vs Discrete LED drivers without calibration)
- Single-cell Li-ion buck-boost topology (vs Buck-only 4-channel LED drivers)
- 1.5 A peak sequential channel current (vs Standard 100 mA to 200 mA per-channel drivers)
Design Notes
Place the input ceramic bypass capacitor (1 uF X5R minimum, 10 V rating) within 2 mm of the VIN pin to minimize high-frequency switching noise on the supply rail. The buck-boost inductor should sit directly over the LX1/LX2 switch-node loop with the smallest possible copper area to limit radiated EMI; Renesas recommends a 4.7 uH to 10 uH shielded inductor with low DCR (<50 mOhm) for efficiency above 90 percent at typical loads.
Solder the exposed thermal pad (EP) of the 28-QFN directly to a continuous ground copper pour on the top layer with at least eight thermal vias to an internal ground plane. Without adequate thermal relief, junction temperature can exceed 125 C at full 1.5 A sequential drive across all four channels; at typical 20 mA to 30 mA per-channel backlight loads, however, self-heating is negligible and no external heatsink is required.
Do not connect the I2C pull-ups to VIN - use VIO (typically 1.8 V from the application processor) instead, otherwise the I2C logic levels will exceed the processor's absolute-maximum ratings. Also ensure the ISET resistor is within the 1 percent tolerance range specified by the datasheet, because LED current accuracy directly depends on this resistor's value and tolerance; a 5 percent part can shift white balance by visible amounts.
Keep the analog ground (AGND) and power ground (GND) tied to a single star point near the IC exposed pad rather than splitting them across the PCB. Route the LED current-sink traces (LED1-LED4) symmetrically and away from the switch-node copper to avoid coupling switching noise into the LED current regulation loop, which would manifest as visible flicker at high PWM duty cycles.
Compliance Information
RoHS compliance confirmed by Renesas/Intersil product page. AEC-Q100 is not applicable - this part is targeted at consumer portable backlighting, not automotive. Halogen-free status not explicitly stated in the available data; mark as unknown.
