IS32BL3554 BOOST TYPE LED DRIVER WITH 4-CHANNEL CURRENT SOURCE September 2015 GENERAL DESCRIPTION FEATURES The IS32BL3554 is a white LED driver for backlight Input voltage range: 4.5V to 33V applications based on a highly efficient boost 180mA per string 4-Channel LED current sinks, controller operating over a wide input voltage range of LED current adjustable from 20mA to 180mA 4.5V to 33V. String-to-string current matching accuracy: 1.5% The IS32BL3554 contains four regulated current Adjustable operating frequency: 100kHz to 1MHz sources with 1.5% (Typ.) current matching between External PWM dimming strings for a uniform LED brightness. Each current High contrast ratio source can be programmed via an external resistor to Less than 3A shutdown current drive from 20mA to 180mA. A fast slew rate current Programmable soft-start source allows high frequency and narrow pulse width Built-in protection features dimming signals to achieve a very high contrast ratio. - OCP, OTP, UVLO The device operating frequency can be adjusted from 0.1MHz to 1MHz. - Open/short LED protection - Programmable OVP The IS32BL3554 has safety protection features to - Schottky Diode/inductor short-circuit protection prevent damage during fault conditions. Protection Automotive AEC-Q100 qualified features include an internal soft-start circuit to prevent a high inrush current during startup, open/short LED protection to automatically disable a faulty current APPLICATIONS source, over temperature protection (OTP), cycle-by-cycle current limit, under voltage lockout Automotive Lighting (UVLO), programmable OVP, VOUT short / Schottky LCD Monitor/TV diode open protection and Schottky Diode LCD Display Module short-circuit protection. The IS32BL3554 is available in a thermally enhanced eTSSOP-16 package. TYPICAL APPLICATION CIRCUIT Figure 1 Typical Application Circuit Integrated Silicon Solution, Inc. www.issi.com 1 Rev. C, 09/01/2015 IS32BL3554 PIN CONFIGURATION Package Pin Configuration (Top View) eTSSOP-16 PIN DESCRIPTION No. Pin Description 1 RT A resistor value to ground sets the switching frequency from 100kHz to 1MHz. Enable Input. The IC is Enabled when this pin is above 2.4V. The IC is Disabled 2 EN and in Shutdown mode when this pin is below 0.5V. In shutdown mode only a minimal 3A current is consumed. Current Sense Input from the switching converter. A sense resistor from the 3 CS source of the external N-MOSFET to GND sets the switching current limit. Switching N-MOSFET Gate Drive Output. This pin outputs a high voltage 4 OUT (5V/V -0.5V) to drive an external switching N-MOSFET. CC 5V linear regulator output. Bypass this pin to GND with a ceramic capacitor as 5 VCC close as possible to the pin. Supply input (4.5V to 33V). Bypass VIN to GND with a capacitor (typical 10F) 6 VIN to keep the DC input voltage constant. 7 STATUS LED operation status will output logic low if a fault is detected. 8 COMP Soft-start and control loop compensation. PWM signal input for LED dimming. If dimming is not implemented, connect it 9 DIM to VCC pin 5. LED current sink 1 and 2 (up to 180mA). If unused leave the pin open 10,11 CH1,CH2 unconnected. 12 GND Ground. Connect all grounds at a single point. LED current sink 3 and 4 (up to 180mA). If unused leave the pin open 13,14 CH3,CH4 unconnected. LED Current Adjust Input. Connect a resistor R between ISET pin and GND ISET 15 ISET to set the reference current through each LED string. Over Voltage Protection pin. Connect a resistor-divider from the switching converter output to this pin. The OVP comparator reference is internally set to 16 OVP 2.0V. Above 2.0V triggers OVP and shuts down switch power switch resumes normal operation when the pin voltage drops below hysteresis voltage. Thermal Pad Connect to GND. Integrated Silicon Solution, Inc. www.issi.com 2 Rev. C, 09/01/2015