ZXLD1615EV1 ZXLD1615EV1 USER GUIDE DESCRIPTION The ZXLD1615 is a PFM inductive boost converter designed to provide LCD and OLED bias voltages of up to 28V from a 2.5V to 5.5V input supply. Nominal output voltage can be set up to a maximum of 28V by two external resistors and can be adjusted to lower values by a PWM control signal applied to the 'Enable' pin. Depending upon the control frequency, the PWM signal will provide either continuous (low ripple) or gated control. The PWM filter components are contained within the chip. Minimum output voltage is determined by the input supply. The ZXLD1615 includes the output switch and peak current sense resistor, and can provide up to 10mA output current at maximum output voltage. Higher current is available at lower output voltages. The device is assembled in a low profile TSOT23-5 pin package. Quiescent current is typically 60A and a shutdown function is provided to reduce this current to less than 100nA in the 'off' state. The ZXLD1615EV1 is configured as for a OLED and LCD bias converter with a single 12V output. ADVANCED FEATURES • Internal 30V NDMOS switch APPLICATIONS • True analogue output voltage control via PWM • Mobile phones with internal filter • Digital cameras FEATURES • Low profile TSOT23-5 pin package • PDAs • Internal PWM filter for flicker free output • LCD modules • High efficiency (80% typ) • Portable internet appliances • Wide input voltage range: 2.5V to 5.5V • Palmtop computers • Up to 50mA output current • Low quiescent current: (60A typ) TYPICAL APPLICATION CIRCUIT • 100nA maximum shutdown current • Up to 1MHz switching frequency • Low external component count ORDERING INFORMATION ORDER NUMBER: ZXLD1615EV1 Please note evaluation boards are subject to availability and qualified leads. ISSUE 1 - OCTOBER 2004 1 SEMICONDUCTORS ZXLD1615EV1 REFERENCE DESIGN ZXLD1615EV1 is configured to the reference design below. The main application is a boost converter for a single 12V output LCD or OLED Bias providing up to 80mA output current at 5V input voltage. For other reference designs or further applications information please refer to the ZXLD1615 datasheet. SCHEMATIC DIAGRAM ABSOLUTE MAXIMUM RATINGS REF VALUE U1 PACKAGE PART NUMBER MANUFACTURER NOTES TSOT23-5 ZXLD1615ET5 Zetex LCD & OLED Bias IC 400mA Schottky Diode D1 400mA SOD323 ZHCS400 Zetex L1 22H 1210 LQH32CN220K21L Murata R1 91k⍀ 0603 Generic Generic R2 1M⍀ 0603 Generic Generic C1 4.7F/10V 0805 Generic Generic X5R dielectric C2 2.2F/25V 0805 Generic Generic X5R dielectric ISSUE 1 - OCTOBER 2004 SEMICONDUCTORS 2 ZXLD1615EV1 CONNECTION DIAGRAM ZXLD1615EV1 OPERATION ZXLD1615EV1 Set-up 1. Connect VIN and GND to positive and zero volts of the power supply respectively. 2. Connect EN pin to positive of power supply. If EN pin is left floating or connected to GND, the ZXLD1615 will be in shutdown mode. 3. Add a 10mA load to VOUT and GND. 4. Set the power supply to 3V. 5. Turn on power supply. Functional check 1. Measure the output voltage with DVM. It should read between 11.4V min and 12.6V max. 2. The PSU input current should read between 40mA min and 55mA max for a functional board. Layout considerations PCB tracks should be kept as short as possible to minimise ground bounce, and the ground pin of the device should be soldered directly to the ground plane. It is particularly important to mount the coil and the input/output capacitors close to the device to minimise parasitic resistance and inductance, which will degrade efficiency. The FB pin is a high impedance input, so PCB track lengths to this should also be kept as short as possible to reduce noise pickup. Excess capacitance from the FB pin to ground should be avoided. Below is the recommended layout of the ZXLD1615EV1. Top Silk LCD &OLED BIAS ZXLD1615EV1 ZDB195R2 Top Copper ZETEX VIN VOUT GND EN GND Bottom Copper Drill File ISSUE 1 - OCTOBER 2004 3 SEMICONDUCTORS ZXLD1615EV1 © Zetex Semiconductors plc 2004 Europe Americas Asia Pacific Corporate Headquarters Zetex GmbH Streitfeldstraße 19 D-81673 München Germany Zetex Inc 700 Veterans Memorial Hwy Hauppauge, NY 11788 USA Zetex (Asia) Ltd 3701-04 Metroplaza Tower 1 Hing Fong Road, Kwai Fong Hong Kong Zetex Semiconductors plc Lansdowne Road, Chadderton Oldham, OL9 9TY United Kingdom Telefon: (49) 89 45 49 49 0 Fax: (49) 89 45 49 49 49 [email protected] Telephone: (1) 631 360 2222 Fax: (1) 631 360 8222 [email protected] Telephone: (852) 26100 611 Fax: (852) 24250 494 [email protected] Telephone (44) 161 622 4444 Fax: (44) 161 622 4446 [email protected] These offices are supported by agents and distributors in major countries world-wide. This publication is issued to provide outline information only which (unless agreed by the Company in writing) may not be used, applied or reproduced for any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned. The Company reserves the right to alter without notice the specification, design, price or conditions of supply of any product or service. For the latest product information, log on to www.zetex.com ISSUE 1 - OCTOBER 2004 SEMICONDUCTORS 4