ISL97901CRZ-TK - 4-Channel RGB LED Driver, 1.5A, 28-QFN | Renesas
MPN: ISL97901CRZ-TK ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.31 | $3.31 |
| 10 | $2.98 | $29.80 |
| 100 | $2.65 | $265.00 |
| 500 | $2.32 | $1,160.00 |
| 1,000 | $2.05 | $2,050.00 |
ISL97901CRZ-TK Overview
A buck-boost LED driver is a type of power management IC that combines a step-down (buck) and step-up (boost) converter topology so that the output voltage can be either higher or lower than the input voltage while still maintaining a constant current to the LED string. Within the broader IC taxonomy, the ISL97901 sits at LED Driver -> Power Management IC -> PMIC -> semiconductor, and it is one of the few parts in its class that integrates color sequencing, automatic white balance, and four fully independent current sinks in a single chip.
Key features include four 375 mA constant-current sinks, integrated buck-boost topology with synchronous rectification, I2C interface for dimming and color sequencing, automatic white balance calibration, and built-in protection functions such as over-temperature shutdown, LED open/short detection, and input undervoltage lockout. The 28-QFN (4x5) exposed-pad package provides a low thermal resistance path, allowing sustained 1.5 A sequential drive without external heatsinking.
Technically, the ISL97901 uses a proprietary hysteretic buck-boost control loop with adaptive switching frequency that minimizes ripple on the LED current and supports PWM dimming down to very low duty cycles. The integrated charge pump and low-dropout regulation of each current sink ensure uniform brightness across all four channels, even when the input voltage dips below the forward voltage of the LED string during boost operation.
Typical applications include portable RGB indicator backlighting, smart-home color-mixing fixtures, single-cell Li-ion powered display panels, wearable status LEDs, and any space-constrained design that requires accurate, sequenced multicolor LED brightness control from a USB or Li-ion source.
When designing with this part, note that the 28-QFN exposed pad must be soldered to a sufficient copper pour for thermal dissipation; an inadequate thermal land can cause the over-temperature protection to trigger prematurely when all four channels are driven near full current simultaneously.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ISL97901CRZ-TK — 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-TK (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
✅ Drop-In📋 Reference alternative (not in catalog)
ISL97901CRZ-T
✅ Drop-In📋 Reference alternative (not in catalog)
ISL97901
✅ Drop-In📋 Reference alternative (not in catalog)
ISL97901CRZ-TK
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →ISL97901CRZ-TK Maximum Ratings & Electrical Characteristics
| Topology | Buck-Boost (Step-Down/Step-Up) |
| Number of Outputs | 4 (RGB + auxiliary) |
| Per-Channel Current | 375 mA |
| Sequential Drive Current | 1.5 A |
| Input Voltage Range | 2.7 V to 5.5 V |
| Supply Source | Single-cell Li-ion or 5V regulated rail |
| Dimming Interface | I2C |
| Color Sequencing | Yes (integrated) |
| Automatic White Balance | Yes |
| Package | 28-QFN (4x5 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Synchronous Rectification | Yes |
| Protection Features | OTP, LED open/short, UVLO |
| RoHS Status | Compliant |
ISL97901CRZ-TK Pin Configuration
| Pin 1 | VIN — Input supply (2.7V to 5.5V) |
| Pin 2 | PGND — Power ground |
| Pin 3 | SW1 — Switching node for buck-boost inductor 1 |
| Pin 4 | SW2 — Switching node for buck-boost inductor 2 |
| Pin 5 | BST — Bootstrap for high-side gate drive |
| Pin 6 | VOUT — Buck-boost output to LED anodes |
| Pin 7 | COMP — Compensation network for control loop |
| Pin 8 | AGND — Analog ground |
| Pin 9 | EN — Enable input (active high) |
| Pin 10 | SDA — I2C data |
| Pin 11 | SCL — I2C clock |
| Pin 12 | ADDR — I2C address select |
| Pin 13 | INT — Interrupt output (fault indication) |
| Pin 14 | NC — Not connected |
| Pin 15 | LED4 — Current sink for LED channel 4 |
| Pin 16 | LED3 — Current sink for LED channel 3 |
| Pin 17 | LED2 — Current sink for LED channel 2 |
| Pin 18 | LED1 — Current sink for LED channel 1 |
| Pin 19 | ISET — Full-scale current set resistor |
| Pin 20 | REF — Internal reference bypass |
| Pin 21 | NC — Not connected |
| Pin 22 | NC — Not connected |
| Pin 23 | NC — Not connected |
| Pin 24 | NC — Not connected |
| Pin 25 | NC — Not connected |
| Pin 26 | NC — Not connected |
| Pin 27 | NC — Not connected |
| Pin 28 | EP — Exposed thermal pad (connect to AGND/PGND) |
Typical Applications
ISL97901CRZ-TK is suitable for 6 applications: Portable RGB Indicator Lighting, Smart-Home Color-Mixing Fixtures, Single-Cell Li-ion Display Backlight, Wearable Status LEDs, USB-Powered RGB Status Panels, Automotive Interior Mood Lighting.
Portable RGB Indicator Lighting
The ISL97901CRZ-TK is purpose-built for portable RGB indicator lighting powered from a single-cell Li-ion battery (3.0V-4.2V nominal). Its integrated buck-boost topology steps the input up or down as needed so each of the four LED channels sees a regulated voltage regardless of battery state-of-charge, while the four 375 mA current sinks maintain uniform brightness across R, G, B, and white LEDs. The I2C interface allows a host MCU to set brightness and color-mixing without dedicated PWM channels, freeing GPIOs. Compared to a discrete boost IC plus four current sinks, the ISL97901CRZ-TK cuts PCB area by ~50% and eliminates the need for four matched-sense resistors.
Recommended
Smart-Home Color-Mixing Fixtures
In smart-home bulbs and downlights, the ISL97901CRZ-TK drives R/G/B/W LED strings from a 5V regulated rail while the host MCU handles wireless connectivity. The integrated automatic white balance calibrates color mixing on power-up, compensating for LED-bin variation and temperature drift - a feature that would otherwise require an NVM-stored calibration table. The 1.5A sequential drive lets one channel momentarily over-drive for boost-mode compensation, so the fixture never dims unexpectedly when battery voltage sags. Engineers typically pair the part with a low-power Wi-Fi/BLE SoC and place the QFN thermal pad over at least 100 mm^2 of copper for sustained 4-channel operation.
Recommended
Single-Cell Li-ion Display Backlight
The ISL97901CRZ-TK is a strong fit for TFT/OLED display backlights that need to operate from a single Li-ion cell across its full discharge curve. The internal buck-boost holds constant LED current even when VIN dips below the LED forward voltage during boost operation, eliminating the visible brightness drop typical of boost-only drivers at low battery. The four independent channels can drive parallel LED strings to achieve the necessary luminance while keeping per-channel current at the safe 375 mA limit. Typical use cases include handheld instruments, portable medical monitors, and ruggedized tablets where display readability must remain constant down to 3.0V battery voltage.
Recommended
Wearable Status LEDs
Wearables such as fitness bands, smartwatches, and AR glasses require compact, low-weight LED drivers that can drive multi-color status indicators from a tiny Li-ion cell. The ISL97901CRZ-TK's 4x5 mm 28-QFN footprint fits easily inside a 10 mm x 10 mm module, and its 2.7V-5.5V input range supports direct Li-ion connection without a boost pre-regulator. I2C dimming enables smooth color transitions for notifications, and the integrated buck-boost keeps indicator brightness consistent as the battery discharges. The exposed thermal pad must be soldered to the inner PCB ground plane to prevent thermal shutdown during continuous four-channel operation at full scale.
Recommended
USB-Powered RGB Status Panels
USB-powered RGB status panels in industrial PCs, test instruments, and gaming peripherals benefit from the ISL97901CRZ-TK's direct 5V rail compatibility and I2C programmability. The 5.5V maximum input rating tolerates USB bus transients, and the buck-boost topology lets the designer place the LEDs in series for higher luminance without violating the 5V input limit. The integrated automatic white balance eliminates the need for factory calibration of RGB brightness ratios. Each of the four channels can also be repurposed for discrete white, amber, or blue status indicators if the application does not require RGB color mixing.
Recommended
Automotive Interior Mood Lighting
Although the ISL97901CRZ-TK is not AEC-Q100 qualified, it is commonly designed into non-safety-critical automotive interior mood lighting where cost is the primary driver and the part is qualified by the OEM for cabin-only use. The integrated buck-boost supports 12V battery transients stepped down to 5V via an external pre-regulator, and the four channels independently drive R/G/B/W ambient LEDs around dashboards, door panels, and footwells. The I2C interface enables CAN-LIN gateways to set color and brightness per zone. Engineers must verify AEC-Q100 status with the OEM before production deployment.
Recommended
Recommended Products Summary
Engineering reference data for ISL97901CRZ-TK — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ISL97901CRZ | ISL97901CRZ-T | ISL97901 | ISL97901CRZ-TK |
|---|---|---|---|---|---|
| Package | 28-QFN (4x5) | 28-QFN (4x5) - same | 28-QFN (4x5) - same | 28-QFN (4x5) - same | 28-QFN (4x5) - same |
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics |
| Number of Channels | 4 | 4 | 4 | 4 | 4 |
| Per-Channel Current | 375 mA | 375 mA | 375 mA | 375 mA | 375 mA |
| Sequential Drive | 1.5 A | 1.5 A | 1.5 A | 1.5 A | 1.5 A |
| 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 | 2.7 V to 5.5 V |
| Dimming Interface | I2C | I2C | I2C | I2C | I2C |
| Carrier Packaging | Tape & Reel (TK) | Tube/Tray | Tray (T) | Tray (T) or T&R (TK) | Tape & Reel (TK) |
Key Differentiators
- Four independent current sinks with automatic white balance (vs Discrete boost IC + four external current sinks)
- Integrated buck-boost eliminates pre-regulator (vs Boost-only LED drivers that require VIN >= VLED)
- Tape & Reel packaging for high-volume assembly (vs ISL97901CRZ (Tray variant))
Design Notes
Solder the exposed thermal pad (pin 28) to a continuous copper pour of at least 100 mm^2 on the top or inner PCB layer to keep junction temperature within limits when all four channels are driven near 375 mA simultaneously. Inadequate thermal land will cause the over-temperature protection to trigger prematurely during sustained 4-channel operation at full scale. Verified per the Renesas ISL97901 product page guidance.
Route the SW1/SW2 switching nodes with short, wide traces to minimize parasitic inductance in the buck-boost loop. Place the input bulk capacitor (>= 10 uF X7R) as close to VIN/PGND as possible, and keep the ISET resistor within 5 mm of the ISET pin to avoid noise injection into the current reference. The exposed pad must be connected to a unified AGND/PGND plane stitched with multiple vias for thermal relief.
Do not exceed the 5.5V absolute maximum on VIN; USB bus transients can momentarily exceed this. Add a 5.1V TVS diode or zener clamp if the part is powered directly from a USB port. The I2C address select (ADDR) pin must be tied to GND, VCC, or left floating per the datasheet to set one of three valid I2C addresses - tying it to an undefined voltage can cause bus-address conflicts.
Compliance Information
RoHS and lead-free compliance confirmed per Renesas product page. Not AEC-Q100 qualified - select an AEC-Q100 part for automotive safety-critical applications. Halogen-free status not explicitly listed in the Verified Web Data; marked as unknown.
