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is32lt3961-zla3-tr
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ISSI Integrated Silicon Solution LED Drivers, TSSOP-16-EP. Datasheet-verified pinout, KiCad symbol/footprint/3D.
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ISSI Integrated Silicon Solution · LED Drivers · TSSOP-16-EP
IS32LT3961-ZLA3-TR from ISSI Integrated Silicon Solution, in a TSSOP-16-EP. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VCC | power_in | Power supply input, 5V to 60V (absolute max 66V). Connect a bypass capacitor CVCC (4.7µF typ.) to ground; route from CVCC to GND and VCC as short as possible. |
| 2 | TON | input | On-time setting pin. Connect a resistor RTON from this pin to VCC to set the constant on-time (switching frequency) for the COT buck controller. |
| 3 | EN/PWM | input | Logic input for enable and PWM dimming. Pull above VIH (2V typ., 1.4V min) to enable, below VIL (0.8V typ., 0.4V) to disable. Accepts a 100Hz-20kHz PWM signal to dim LED brightness. High-voltage tolerant; internal 200kΩ pull-down. |
| 4 | AGND | power_in | Analog ground reference for the internal control circuitry and small-signal setting components. |
| 5 | FAULTB | output | Open-drain diagnostic output. Active low to indicate fault conditions (LED open/short, single LED short, RIS/BOOT/RTON faults, thermal shutdown, etc.). Requires external pull-up (typ. 10kΩ). VOL ≤ 0.2V at IOL = 5mA; leakage ≤ 1µA with 6V pull-up. |
| 6 | VDD | power_out | Internal 6V (typ., 5.8-6.2V) LDO output that powers internal control circuits. Connect a 1µF X7R ceramic cap to GND placed as close to VDD as possible. May supply reference to ADIM or pull-up for FAULTB; current limit 22-37mA. |
| 7 | ADIM | input | Analog dimming input. Voltage 0.4V-2V linearly scales the current-sense regulation threshold (VIS); >2.1V disables analog dimming (100% output); <0.28V forces output off. Never leave floating. Input current: 0nA (VADIM<2V), −25nA (VADIM>2V). |
| 8 | IMON | output | Output current monitor. Analog buffered voltage representing the LED current: VIMON = (VISP − VISN) × 8 + 0.4V. Up to ~VDD (6V). Can drive host ADC through a resistor divider if needed. |
| 9 | SCD | input | LED short-circuit detection threshold input. Connect a resistor divider (RSCD1/RSCD2) from LED+ to GND. FAULTB asserts when VSCD falls below VSCD_TH (1.15V typ., 50mV hysteresis). Never leave floating; if unused, tie to ISN via 10kΩ. |
| 10 | ISN | input | Current-sense negative input for the high-side LED current sense resistor RIS. Together with ISP forms the average LED current sense (VIS = 200mV typ. for 100% load). |
| 11 | ISP | input | Current-sense positive input. Sense element RIS is connected between ISP and ISN across the high-side path. ISP bias current: 176µA (VISN=12V) or −50µA (VISN=0V). |
| 12 | VOUT | input | Output voltage sense pin. Feeds the COT timer and control loop with the buck output voltage information. |
| 13 | SGND | power_in | Power/signal ground for the low-side current sense. The CS sense resistor RCS MUST be connected to this ground pin for precise sensing. |
| 14 | CS | input | Current ripple sense input. Senses the inductor current ripple during the high-side MOSFET off-time via low-side resistor RCS for loop control, valley current limit (VCS_TH1 = 50mV typ.), and inductor peak current limit (VCS_TH2 = 100mV typ.). |
| 15 | BOOT | passive | Bootstrap capacitor node for the internal high-side MOSFET gate driver. Connect a 0.1µF X7R ceramic capacitor from BOOT to LX. Internal 5.5V LDO charges CBOOT during off-time; UVLO at 2.85V rising / 2.5V falling. |
| 16 | LX | output | Internal high-side MOSFET switch node output. Connect to the buck inductor and Schottky recirculating diode. Steady-state −0.6V to VCC+0.3V; transient (<10ns) tolerant down to −3V. RDS_ON ≈ 0.2Ω. |
| 17 | EP | power_in | Exposed thermal pad on the underside of the eTSSOP-16 package. Connect to GND and solder to a copper ground plane with thermal vias for heat dissipation (θJP = 1.617°C/W). |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | ISSI Integrated Silicon Solution |
| Package | TSSOP-16-EP |
| Category | LED-drv |
| Pins | 17 |
Ordering variants
IS32LT3961-ZLA3-TR
CAD (KiCad official)
- Symbol:
IS32LT3961-ZLA3-TR - Footprint:
Package_SO:TSSOP-16-1EP_4.4x5mm_P0.65mm - 3D model: TSSOP-16-EP (KiCad packages3D, STEP)
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: ISSI Integrated Silicon Solution datasheet (None pp, sha256
5d23aa88a49cb7dd, retrieved 2026-08-17, tier: lcsc) - Extractor:
ds2sf(Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate. - CAD: KiCad official libraries (CC-BY-SA 4.0).