IC LED DRVR WHITE BCKLGT 28-TQFN

MAX8645YETI+

Manufacturer Part NumberMAX8645YETI+
DescriptionIC LED DRVR WHITE BCKLGT 28-TQFN
ManufacturerMaxim Integrated Products
TypeBacklight, White LED
MAX8645YETI+ datasheet
 


Specifications of MAX8645YETI+

Constant CurrentYesTopologyLinear (LDO), Switched Capacitor (Charge Pump)
Number Of Outputs8Internal DriverYes
Type - PrimaryBacklightType - SecondaryWhite LED
Frequency1MHzVoltage - Supply2.7 V ~ 5.5 V
Voltage - Output5.5VMounting TypeSurface Mount
Package / Case28-TQFN Exposed PadOperating Temperature-40°C ~ 85°C
Current - Output / Channel200mAInternal Switch(s)Yes
Efficiency85%Number Of Segments8
Low Level Output Current400000 uA (Typ)Operating Supply Voltage2.7 V to 5.5 V
Maximum Supply Current5.5 mAMaximum Power Dissipation1666 mW
Maximum Operating Temperature+ 85 CMounting StyleSMD/SMT
Minimum Operating Temperature- 40 CLed Driver ApplicationBacklighting And Flash, Digital Cameras And Camcorders
No. Of Outputs8Output Current200mA
Output Voltage5.5VInput Voltage2.7V To 5.5V
Rohs CompliantYesLead Free Status / RoHS StatusLead free / RoHS Compliant
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19-3978; Rev 4; 6/08
1x/1.5x/2x White LED Charge Pumps with
General Description
The MAX8645X/MAX8645Y charge pumps drive up to
eight white LEDs with regulated constant current for uni-
form intensity. The main group of LEDs (M1–M6) can be
driven up to 30mA per LED for backlighting. The flash
group of LEDs (F1 and F2) is independently controlled
and can be driven up to 200mA per LED (or 400mA total).
Two 200mA LDOs are on-board to provide power for
camera functions. The LDOs’ output voltages are pin pro-
grammable to meet different camera-module require-
ments. The MAX8645X and MAX8645Y differ only in LDO
output voltages. By utilizing adaptive 1x/1.5x/2x charge-
pump modes and very-low-dropout current regulators,
the MAX8645X/MAX8645Y achieve high efficiency over
the full 1-cell lithium-battery voltage range. The 1MHz
fixed-frequency switching allows for tiny external compo-
nents, and the regulation scheme is optimized to ensure
low EMI and low input ripple.
The MAX8645X/MAX8645Y are available in a 28-pin TQFN,
4mm x 4mm (0.8mm max height) lead-free package.
Camera Phones and Smartphones
Backlighting and Flash
PDAs, Digital Cameras, and Camcorders
Typical Operating Circuit
1μF
1μF
OUTPUT
INPUT
C1P
C1N
C2P
C2N
UP TO 580mA
2.7V TO 5.5V
OUT
PIN
10μF
IN
10μF
MAX8645X
GND
MAX8645Y
M1
PGND
M2
M3
M4
ENM1
MAIN ON/OFF
M5
AND DIMMING
ENM2
M6
F1
ENF
FLASH ON/OFF
F2
LDO1
ENLDO
DUAL-LDO ON/OFF
LDO2
DUAL-LDO
P1
1μF
VOLTAGE
SELECTION
P2
SETM
SETF
REF
0.01μF
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim's website at www.maxim-ic.com.
Two LDOs in 4mm x 4mm TQFN
♦ Power Up to Eight LEDs
Up to 30mA/LED Drive for Backlight
Up to 400mA Total Drive for Flash
♦ Two Internal Low-Noise 200mA LDOs
♦ 94% Max/85% Avg Efficiency (P
Battery Discharge
♦ 0.2% Typical LED Current Matching
♦ Adaptive 1x/1.5x/2x Mode Switchover
♦ Single-Wire, Serial-Pulse Interface for Brightness
Control (32 Steps)
♦ Thermal T
♦ Low Input Ripple and EMI
♦ 2.7V to 5.5V Supply Voltage Range
♦ Soft-Start, Overvoltage, and Thermal-Shutdown
Applications
Protection
♦ 28-Pin TQFN, 4mm x 4mm Package
PART
MAX8645XETI+
MAIN
FLASH
MAX8645YETI+
EP = Exposed pad.
+ Denotes a lead-free package.
CAMERA
MODULE
1μF
Pin Configuration appears at end of data sheet.
Features
/P
) over Li+
LED
BATT
Derating Function
A
Ordering Information
TEMP RANGE
PIN-PACKAGE
28 TQFN-EP
-40°C to +85°C
4mm x 4mm
28 TQFN-EP
-40°C to +85°C
4mm x 4mm
1

MAX8645YETI+ Summary of contents

  • Page 1

    ... Supply Voltage Range ♦ Soft-Start, Overvoltage, and Thermal-Shutdown Applications Protection ♦ 28-Pin TQFN, 4mm x 4mm Package PART MAX8645XETI+ MAIN FLASH MAX8645YETI Exposed pad. + Denotes a lead-free package. CAMERA MODULE 1μF Pin Configuration appears at end of data sheet. Features /P ) over Li+ ...

  • Page 2

    White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN ABSOLUTE MAXIMUM RATINGS PIN, IN, OUT, REFBP to GND................................-0.3V to +6.0V SETF, SETM, ENLDO, ENM1, ENM2, ENF, P1, P2, LDO1, LDO2 to GND....................-0. M1, M2, ...

  • Page 3

    White LED Charge Pumps with Two ELECTRICAL CHARACTERISTICS (continued 3.6V 0V, ENM1 = ENM2 = ENF = IN GND PGND T = -40°C to +85°C, unless otherwise noted. Typical values are ...

  • Page 4

    White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN ELECTRICAL CHARACTERISTICS (continued 3.6V 0V, ENM1 = ENM2 = ENF = IN GND PGND T = -40°C to +85°C, ...

  • Page 5

    White LED Charge Pumps with ( 3.6V, circuit of Figure EN_ BATTERY CURRENT vs. SUPPLY VOLTAGE DRIVING FLASH 900 800 700 I = 400mA FLASH 600 500 I = 160mA FLASH 400 I ...

  • Page 6

    White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN ( 3.6V, circuit of Figure EN_ INDIVIDUAL FLASH LED CURRENT vs. R 2000 200 SETF OPERATING ...

  • Page 7

    White LED Charge Pumps with Two ( 3.6V, circuit of Figure EN_ SINGLE-WIRE DIMMING RESPONSE V ENM1, V ENM2 I OUT V OUT 10ms/div LDO OUTPUT VOLTAGE ACCURACY vs. OUTPUT CURRENT 1.0 0.8 ...

  • Page 8

    White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN PIN NAME Supply Voltage Input. Bypass to PGND with a 10µF ceramic capacitor. The input voltage range is 1 PIN 2.7V to 5.5V. PIN is high impedance ...

  • Page 9

    ... MAX8645Y start switching in 2x mode. When the input voltage rises above 2 approximately 50mV, OUT the MAX8645X/MAX8645Y switch back to 1.5x mode. True Shutdown is a trademark of Maxim Integrated Products, Inc. _______________________________________________________________________________________ LDOs in 4mm x 4mm TQFN FUNCTION The MAX8645X/MAX8645Y include soft-start circuitry to limit inrush current at turn-on. Once the input voltage is ...

  • Page 10

    White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN INITIAL t HI ≥ 200μ ENM1 AND ENM2 OR t SOFT-START ENF 32/ SHUTDOWN Figure 1. ENM_ and ENF Timing ...

  • Page 11

    White LED Charge Pumps with Two INPUT 2.7V TO 5.5V C1 10μF MAIN ON/OFF AND DIMMING FLASH ON/OFF AND DIMMING ON/OFF VOLTAGE SELECTION Figure 2. Dimming Using Single-Wire, Serial-Pulse Interface INPUT 2.7V TO 5.5V 10μF ON/OFF AND VOLTAGE SELECTION ...

  • Page 12

    White LED Charge Pumps with Two LDOs in 4mm x 4mm TQFN INPUT 2.7V TO 5.5V 10μF ON/OFF AND VOLTAGE SELECTION Figure 4. Schematic for When Fewer than 8 LEDs Are Acceptable Typical operating waveforms shown in the Typical ...

  • Page 13

    White LED Charge Pump with Table 3. Recommended Components for Figure 2 DESIGNATION VALUE MANUFACTURER C1, C5 10µF C3, C4, C6, C7 1µF C8 0.01µF D1–D4 — D5 (D5–D8) — Panasonic SETM SETF required PCB ...

  • Page 14

    ... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 14 © 2008 Maxim Integrated Products ...