lp5527tlx National Semiconductor Corporation, lp5527tlx Datasheet

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lp5527tlx

Manufacturer Part Number
lp5527tlx
Description
Tiny Led Driver For Camera Flash And 4 Leds With I2c Programmability, Connectivity Test And Audio Synchronization
Manufacturer
National Semiconductor Corporation
Datasheet

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© 2006 National Semiconductor Corporation
LP5527
Tiny LED Driver for Camera Flash and 4 LEDs with I
Programmability, Connectivity Test and Audio
Synchronization
General Description
The LP5527 is a lighting management unit for handheld
devices with I
has a step-up DC/DC converter with high current output and
it drives display and keypad backlights and powers the cam-
era flash LED. In addition the DC/DC converter has the
output current to power for example an audio amplifier si-
multaneously. The chip has four 8-bit programmable high
efficiency constant current LED drivers and a FLASH LED
driver. Built-in audio synchronization feature allows the user
to synchronize one of the LEDs to audio input.
The LP5527 has an integrated 400 mA flash driver with a
safety stop feature and 50 mA torch mode. An external
enable pin is provided for the synchronizing the flash with the
camera action. An external software independent test inter-
face provides a fast way to find a broken path or short on
LED circuits. Very small microSMD package together with
minimum number of external components is a best fit for
handheld devices.
Typical Application
2
C compatible control interface. The LP5527
DS201840
Features
n High current boost DC-DC converter (up to 1A output
n Programmable boost output voltage
n 400 mA flash LED constant current driver with low
n Synchronization pin for the flash timing
n Two single-ended audio inputs with gain control
n Four constant current 15 mA LED drivers with 8-bit
n Audio synchronization feature
n I
n Built-in LED connectivity test to maximize manufacturing
n Small microSMD-30 package (2.5 mm x 3.0 mm x 0.6
Applications
n Camera FLASH, funlight and backlight driving in battery
current)
tolerance and a safety circuit
programmable brightness control
yield
mm)
powered devices
2
C compatible control interface
20184001
www.national.com
2
May 2006
C

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lp5527tlx Summary of contents

Page 1

... LED circuits. Very small microSMD package together with minimum number of external components is a best fit for handheld devices. Typical Application © 2006 National Semiconductor Corporation Features n High current boost DC-DC converter ( output current) n Programmable boost output voltage ...

Page 2

... Connection Diagrams and Package Mark Information Connection Diagrams microSMD-30 package, 2.466 x 2.974 x 0.60 mm body size, 0.5 mm pitch NS Package Number TLA3011A Top View PACKAGE MARK ORDERING INFORMATION Order Number LP5527TL LP5527TLX www.national.com 20184002 20184004 Top View XY — Date Code TT — Die Traceability 5527 — Product Identification ...

Page 3

Connection Diagrams and Package Mark Information 2.974 x 0.60 mm body size, 0.5 mm pitch NS Package Number TLA3011A (Continued) Pin Descriptions Pin Name Type D3 VDD1 A1 VDD2 F5 SW1 E5 SW2 LED1 O A5 LED2 ...

Page 4

Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Voltage on power pins (V ) DD1,2 Voltage on analog pins Voltage on input/output pins V(all other pins): Voltage ...

Page 5

LP5527 Block Diagram 5 20184005 www.national.com ...

Page 6

Modes of Operation RESET: In the reset mode all the internal registers are reset to the default values. Reset is entered always if input NRST is LOW or internal Power On Reset (POR) is active. Power on reset will activate ...

Page 7

Magnetic Boost DC/DC Converter The LP5527 boost DC/DC converter generates a 4.55 – 5.00V output voltage to drive the LEDs from a single Li-Ion battery (3.0V to 4.5V). The output voltage is controlled with a 4-bit register in 4 steps. ...

Page 8

Magnetic Boost DC/DC Converter MAGNETIC BOOST DC/DC CONVERTER ELECTRICAL CHARACTERISTICS Limits in standard typeface are for T < < range (- +85 C). Unless otherwise noted, specifications apply to the LP5527 Block Diagram with ...

Page 9

Boost Converter Typical Performance Characteristics Unless otherwise noted, typical performance characteristics apply to the LP5527 Block Diagram with 5.0V µ µ OUT1 OUT2 = ...

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Boost Converter Typical Performance Characteristics Boost Load Transient Response 100 mA www.national.com Boost Maximum Output Current 20184085 10 (Continued) 20184098 ...

Page 11

Flash Driver LP5527 has an internal constant current driver that is ca- pable for sinking low (50 mA) and high (400 mA) current mainly targeted for torch and flash LED in camera phone applications. 400 mA flash driver can be ...

Page 12

Constant Current Sink Outputs LED1, LED2, LED3, LED4 LP5527 has four independent backlight/keypad LED drivers. All the drivers are regulated constant current sinks. LED currents are controlled by 8-bit current mode DACs. Every driver can be controlled in two ways: ...

Page 13

Audio Synchronization The LED1 output can be synchronized to incoming audio signal with Audio Synchronization feature. Audio Synchroni- zation synchronizes LED1 based on input signal’s peak am- plitude. Programmable gain and automatic gain control func- tion are also available for ...

Page 14

Audio Synchronization Audio Input Threshold Setting Threshold[3:0] Threshold Level, mV (typical) 0000 0001 0010 * * 1110 1111 Typical Gain Values vs. Audio Input Amplitude Audio Input Amplitude mV P ...

Page 15

I C Compatible Interface SIGNALS 2 The SCL pin is used for the I C clock and the SDA pin is used for bidirectional data transfer. Both these signals need 2 a pull-up resistor according to ...

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I C Compatible Interface w = write (SDA = “0” read (SDA = “1”) ack = acknowledge (SDA pulled down by either master or slave repeated start id = chip address, 4C hex for LP5527. ...

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I C Compatible Interface 10 Bus Free Time between a STOP and a START Condition C Capacitive Load for Each Bus Line b NOTE: Data guaranteed by design Test Interface The test bus can be controlled externally or internally. ...

Page 18

Test Interface (Continued) Test Interface Timing Parameters Symbol Condition 4.2V DD1 NOTE: Data guaranteed by design Test Interface Characteristics Limits in standard typeface are for T Symbol Parameter Logic Input T1 V Input ...

Page 19

Recommended External Components OUTPUT CAPACITOR OUT1 OUT2 The output capacitors directly affect the mag- OUT1 OUT2 nitude of the output ripple voltage. In general, the higher the value the lower the ...

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www.national.com 20 ...

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Physical Dimensions inches (millimeters) unless otherwise noted The dimension for X1, X2 and X3 are as given: • 2.466 mm ± 0.03 mm • 2.974 mm ± 0.03 mm • 0.60 mm ± 0.075 ...

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