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ILC6383
1-Cell to 3-Cell Boost DC-DC Converter with True Load Disconnect, 3.3V, 5V or Adjustable Output
Features
• • • • • • • • • • • • Guaranteed start up in PWM at 0.9V input Synchronous rectification requires no external diode True load disconnect from battery input in shutdown Up to 75mA at 3.3V and 40mA at 5V from 1V input Up to 375mA at 3.3V and 300mA at 5V from 3V input Peak efficiency > 90% 1µA battery input current in shutdown (with VOUT = 0V) Internal Oscillator frequency: 300kHz to ±15% ILC6383: Fixed 3.3V or 5V output ILC6383-ADJ: Adjustable output to 6V maximum Low battery detector with 100ms transient rejection delay Powergood output flag when VOUT is in regulation
Description
The ILC6383 series of step-up DC-DC converters operate from 1-cell to 3-cell input. They are direct replacement for ILC6382, in applications where SYNC pin is not used. The PFM or PWM operating mode is user selectable through SEL pin connected to ground or left open, respectively. The choice should be dependent upon the current to be delivered to the load: PFM is recommended for input voltage higher than 1.5V and loads below 100mA, while PWM is recommended for more than 50mA load current and in noise sensitive applications. In shutdown mode, the device allows true load disconnect from battery input. Designed for wireless communications applications, the oscillator frequency is set at 300kHz with no harmonics at sub 20kHz audio band or at 455kHz IF band. Internal synchronous rectification and externally selectable PFM/PWM mode of operation allows the selection of the best efficiency at light or full load. The ILC6383 is capable of delivering 75mA at 3.3V output from a single cell input. The ILC6383-XX offers 3.3V or 5V fixed output voltage while the ILC6383-ADJ allows adjustable output voltage to 6V maximum. Output voltage accuracy is ±3.5% over full operating temperature range. Additional features include power good output (POK) and an internal low battery detector with 100ms transient rejection delay. The device will reject low battery input transients under 100ms in duration. The ILC6383 series is available in a space saving eight lead micro SOP (MSOP-8) package.
Applications
• Cellular Phones, Pagers • Palmtops, PDAs and portable electronics • High efficiency 1V step up converters
Typical Applications
CIN 47µF + VIN 1 to 3-cell ON OFF L 1 15µH 2 VIN R5 3 LBI/SD R6 4 SEL LBO 6 POK 5 Low Battery Detector Output Power Good Output ILC6383-XX LX VOUT 8 GND 7 + 47µF COUT VOUT VIN 1 to 3-cell ON OFF R6 4 SEL VFB 5 R2 CIN 47µF + L 1 15µH 2 R5 3 LBI/SD LBO 6 VIN GND 7 ILC6383-ADJ LX VOUT 8 + VOUT
COUT 47µF
R1
MSOP-8 PWM PFM PWM PFM
MSOP-8
VOUT = 1.25 (1+R1/R2)
Figure 1. ILC6383CIR-XX
Figure 2. ILC6383CIR-ADJ
REV. 1.2.6 6/13/02
ILC6383
PRODUCT SPECIFICATION
Pin Assignments
LX 1 VIN 2 LB/SD 3 SEL 4 MSOP
(TOP VIEW)
8 VOUT 7 GND 6 LBO 5 POK
LX
1
8 VOUT 7 GND 6 5 MSOP
(TOP VIEW)
VIN 2 LB/SD 3 SEL 4
LBO VFB
ILC6383CIR-XX
ILC6383CIR-ADJ
Pin Definitions
Pin Number 1 2 3 Pin Number LX VIN LBI/SD Pin Description Inductor input. Inductor L connected between this pin and the battery Input Voltage. Connect directly to battery Low battery detect input and shutdown. Low battery detect threshold is set with this pin using a potential divider. If this pin is pulled to logic low then the device will shutdown. Select Input. A low logic level signal applied to this pin selects PFM operation mode. If the pin is left open or high logic level is applied, PWM mode is selected. Power Good Output. This open drain output pin will go high when output voltage is within regulation, 0.92*VOUT(NOM) < Vthreshold < 0.98*VOUT(NOM)
4
SEL
5
POK (ILC6383CIR-XX)
VFB Feedback Input. This pin sets the adjustable output voltage via an (ILC6383CIR-ADJ) external resistor divider network. The formula for choosing the resistors is shown in the “Applications Information” section. 6 7 8 LBO GND VOUT This open drain output will go low if the battery voltage is below the low battery threshold set at pin 3 Ground of the IC. Connect this pin to the battery and system ground Regulated output voltage.
Absolute Maximum Ratings (Note 1)
Parameter Voltage on VOUT pin Voltage on LBI, Sync, LBO, POK, VFB, LX and VIN pins Peak switch current on LX pin Current on LBO pin Continuous total power dissipation at 85˚C Short circuit current Operating ambient temperature Maximum junction temperature Storage temperature Lead temperature (soldering 10 sec.) Package thermal resistance θJA Symbol VOUT ILX ISINK(LBO) PD ISC TA TJ(MAX) Tstg Ratings -0.3 to 7 -0.3 to 7 1 5 315 Internally protected (1 sec. duration) -40 to 85 150 -40 to 125 300 206 Units V V A mA mW A °C °C °C °C °C/W
2
REV. 1.2.6 6/13/02
PRODUCT SPECIFICATION
ILC6383
Electrical Characteristics ILC6383CIR-33 in PFM Mode (SEL in LOW State) Unless otherwise specified, all limits are at VIN = VLBI = 2.0V, IOUT = 1mA and TA = 25°C, test circuit Figure 1. BOLDFACE type indicates limit that a.