OCP8111 datasheet Ver 1.4 20130204

1.0A Buck/Boost Charge Pump LED Driver

General Description

󰂄 Features

The OCP8111 is current-regulated charge pump z Output Current up to 1.0A at VIN=4.2V

z Up to 94% Efficiency in Torch Mode ideal for powering high brightness LEDs for camera

flash applications. The charge pump can be set to z Adjustable FLASH Mode Current

regulate two current levels for FLASH and TORCH z Minimum External Components: No Inductors modes. z Automatic Buck/Boost Mode Switchover

The OCP8111 automatically switches modes z Wide VIN Range: 2.7V to 5.5V

between step-up and step-down ensuring that LED z High Frequency Operation: 1.8MHz

z 50mV Reference for low Loss Sensing current does not depend on the forward voltage. It

switches at 1.8MHz, allowing the use of tiny z ISD < 1μA in Shutdown components. The supply voltage ranges from 2.7V to z PWM Dimming Control 5.5V and is ideally suited for all applications powered by z Automatic Soft Start Limits Inrush Current

a single Li_Ion battery cell or three to four NiCd, NiMH, z Over Voltage Protection on Output

z Over Current Protection or Alkaline battery cells.

The OCP8111 also features a very low shutdown z Over Temperature Protection

z Low Input and Output Ripple and Low EMI current (less than 1uA), an automatic soft-start mode to

limit inrush current, as well as over current, over voltage z Ultra-low Dropout Voltage in Buck Mode and over temperature shutdown control. z Space Saving RoHS Compliant, Lead Free

A Low current sense reference voltage (50mV) Package: 10-pin 3mm x 3mm DFN

allows the user of small 0603 current sensing resistors. The OCP8111 is offered in Green 10-pin DFN

󰂄 Applications

package and is specified over an ambient temperature z White LED Torch/Flash for Cell Phones, DSCs, range of -40˚C to 85˚C. and Camcorders z White LED Backlighting z Generic Lighting/Flash/Strobe Applications z General Purpose High Current Boost

󰂄 Pin Configuration

DFN3030-10L (Top View)

Figure 1, Pin Assignments of OCP8111

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OCP8111

Pin Name Pin No. DFN3030-10 1.0A Buck/Boost Charge Pump LED Driver

Pin Function Input Voltage for the charge pump. Decouple with 4.7µF or 10uF ceramic capacitor VIN 1 close to the pins of the IC. Positive input for the external flying capacitor. Connect a ceramic 1 µF capacitor C1 2 close to the pins of the IC. Negative input for the external flying capacitor. Connect a ceramic 1 µF capacitor C2 3 close to the pins of the IC. Logic input to toggle operation between FLASH and TORCH mode. In TORCH mode FB is regulated to the internal 50mV reference. In FLASH mode FB reference voltage can be adjusted by changing the resistor from RSET pin to FLASH 4 ground. Choose the external current sense resistor (RSENSE) based on desired current in TORCH mode. This pin does not have an internal pull-up/pull- down; do not leave this pin floating. Shutdown control input. Connect to VIN for normal operation, connect to ground for EN 5 shutdown. Don’t leave this pin floating. Connect a resistor from this pin to ground. When in FLASH mode (FLASH = High) this resistor sets the current regulation point according to the following: RSET 6 14uA*RSET (Flash Mode) VFB=5Feedback input for the current control loop. Connect directly to the current sense FB 7 resistor. SGND PGND 8 9 Internal ground pin. Control circuitry returns current to this pin. Power ground pin. Flying capacitor current returns through this pin. Charge Pump Output Voltage. Decouple with an external capacitor. At least 1 µF is VOUT 10 recommended. Higher capacitor values reduce output ripple GND Exposed Pad Exposed pad should be soldered to PCB board and connected to GND.

󰂄 Typical Application Circuit

Figure 2, Typical Application Circuit of OCP8111

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OCP8111

1.0A Buck/Boost Charge Pump LED Driver

󰂄 Block Diagram

Figure 3, Block Diagram of OCP8111

󰂄

Absolute Maximum Ratings1 (TA=25°C unless otherwise noted)

Parameter Symbol Rating Unit Input Voltage V VIN -0.3 to 6

VEN ,ISET,VOUT Voltage -0.3 to VIN V Storage Temperature Range TS -55 to +150 ℃ Operating Junction Temperature Range TJ -40 to 150 ℃

Maximum Power Dissipation PD 1.9 W Maximum Thermal Resistance θJA 51 ℃/W

ESD (HBM) ESD 4K V

Output Current Pulse (Flash) IOUT 1.6 A Output Current Continuous (Torch) IOUT 0.4 A

󰂄 Recommended Operating Conditions (TA=25°C unless otherwise noted)

Parameter Supply Voltage

Operating Temperature Range

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Symbol Conditions Rating Unit VIN Operating 2.7 ~ 5.5 V TA Operating -40 ~ +85 ℃

OCP8111

󰂄 Electrical Characteristics

(Unless otherwise noted，typical values are at TA=25℃, VIN=3.6V, CFC=1uF, COUT=10uF) Symbol Parameter Conditions Min. Typ. Max. UnitInput Power Supply VIN Input Voltage range 2.7 - 5.5 V ISD Shutdown Current EN=0V,Shutdown mode - 0.1 1 μA

VIN = 2.7 - 5.5V, FLASH = GND,

- 0.34 2 mA

1X Mode, ILOAD=100μA IQ Quiescent Current

FLASH = HIGH, 2X Mode - 1.75 - mAFLASH = GND 45 50 55 mV

VFB FB Reference voltage

FLASH = High, RSET = 53.6 kΩ138 150 162 mVFLASH = High. Guaranteed by

mV 100 - 400 VFBR FB Reference Voltage Range

design.

IFB FB Pin Current VFB= 0.3V - - 1 μA Charge Pump Section

Charge Pump Equivalent VFB = 0.0V, VIN= 3.6V R2X - 4 - Ω

Resistance (x2 mode)

Charge Pump Equivalent R1X VIN= 3.6V - 0.4 0.7 Ω

Resistance (x1 mode)

VIN= 3.6V, FB within 90% of TSS VOUT Turn-on Time - 140 250 μs

regulation

FOSC Switching Frequency - 1.8 - MHzVOUT Over-voltage Limit LED unconnected, V=V IN 4.2V - 5.1 - TSD Shutdown Temperature Temperature rising - 145 - ℃ TRT Recovery Temperature Temperature falling - 135 - ℃ ENABLE

VENL Enable Threshold Low - - 0.4 V VENH Enable Threshold High 1.4 - - V ILK EN, FLASH Pin Current - - 1 μA TFLASH Maximum Flash ON time FLASH = High 1.2 - 3.8 s

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1.0A Buck/Boost Charge Pump LED Driver

OCP8111

1.0A Buck/Boost Charge Pump LED Driver

󰂄 Typical Performance Characteristics:

(Unless otherwise noted，TA=25℃, VIN=3.6V, CIN=10uF, CFC=1uF, COUT=10uF)

Figure 4, Output Current vs. Supply Voltage Figure 5, VFB vs. RSET Resistance

Figure 6, Flash 700mA Output Current vs. VIN Figure 7, Torch Output Current vs. VIN

Figure 8, Torch in 1X to Flash in 1X, VIN=4.2V Figure 9, Torch in 1X to Flash in 2X, VIN=3.6V

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OCP8111

1.0A Buck/Boost Charge Pump LED Driver

󰂄 Typical Performance Characteristics:

(Unless otherwise noted，TA=25℃, VIN=3.6V, CIN=10uF, CFC=1uF, COUT=10uF)

Figure 10, 250mA Torch, VIN=3.6V, VF=3.1V Figure 11, 250mA Torch, VIN=4.2V, VF=3.1V

Figure 12, 850mA Flash in 1X, VIN=4.2V, VF=3.1V Figure 13, 850mA Flash in 2X, VIN=3.6V, VF=3.1V

Figure 14, Start Up 850mA Flash, VIN=3.6V, VF=3.1V Figure 15, Start Up 850mA Flash, VIN=3.6V, VF=3.9V

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OCP8111

1.0A Buck/Boost Charge Pump LED Driver

󰂄 Typical Performance Characteristics:

(Unless otherwise noted，TA=25℃, VIN=3.6V, CIN=10uF, CFC=1uF, COUT=10uF)

Figure 16, Ripple Torch 250mA in 1X, VIN=4.2V Figure 17, Ripple Torch 250mA in 2X, VIN=3V

Figure 18, Ripple Flash 700mA in 2X Mode, VIN=3.6V Figure 19, Ripple Flash 700mA in 1X Mode, VIN=4.2V

Figure 20, Ripple Flash 850mA in 2X Mode, VIN=3.6V Figure 21, Ripple Flash 850mA in 1X Mode, VIN=4.2V

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OCP8111

1.0A Buck/Boost Charge Pump LED Driver

󰂄 Typical Performance Characteristics:

(Unless otherwise noted，TA=25℃, VIN=3.6V, CIN=10uF, CFC=1uF, COUT=10uF)

Figure 22, PWM Dimming, VIN=4.2 Figure 23, Over-Voltage Protection Waveform

Figure 24, 1A Application Waveform

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OCP8111

1.0A Buck/Boost Charge Pump LED Driver

󰂄 Functional Description

The OCP8111 is a charge pump regulator designed for converting a Li-Ion battery voltage of 2.7V to 4.2V to drive a white LED used in digital still camera Flash and Torch applications. The OCP8111 has two modes of operation which are pin-selectable for either Flash or Torch. Flash mode is usually used with a pulse of about 200 to 300 milliseconds to generate a high intensity Flash. Torch can be used continuously at a lower output current than Flash and is often used for several seconds in a digital still camera “movie” mode.

The OCP8111 also has two modes of operation to control the output current: the 1 X mode and 2X mode. Operation begins after the enable pin EN receives a logic high, then OCP8111 goes through a soft-start mode designed to reduce inrush current. The OCP8111 starts in the 1X mode, which acts like a linear regulator to control the output current by continuously monitoring the feedback pin FB. In 1 X mode, if the OCP8111 auto detects a dropout condition, which is when the FB pin is below the regulation point for more than cycles of the internal clock, the OCP8111 automatically switches to the 2X mode. The OCP8111 remains in the 2X mode until one of three things happens:

1) The enable pin EN has been toggled

2) The Flash pin has changed from high to low 3) VIN is cycled

The 2X mode is the charge pump mode where the output can be pumped as high as two times the input voltage, provided the output does not exceed the maximum voltage for the OCP8111, which is internally limited to about 5.1V. In the 2X mode, as in the 1 X mode, the output current is regulated by the voltage at the FB pin.

In the Torch mode, (Flash = GND) the Flash pin is set to logic low and the OCP8111 FB pin regulates to 50mV output:

VFB = 50mV (Torch Mode)

When in Flash mode, (Flash = VIN), the FB regulation voltage is set by the resistor RSET connected between the RSET pin and SGND and the equation:

VFB=

14uA*RSET

(Flash Mode)

5

Where 14μA is an internal regulated current and 5 is an internal factor used to scale the VSET voltage to the VFB voltage. Typical values of RSET are 140KΩ to 35KΩ for a range of VFB = 400mV to 100mV in Flash mode.

The output current is then set in either Flash or Torch mode by the equation:

IOUT=

VFB

RSENSE

FLASH Timeout Protection:

Due to the high currents typically available in Flash mode, it is necessary to protect the white LED from damage if left on too long. The OCP8111 has a timeout in Flash mode of about 1.2seconds to 3.8seconds after which it will shut down operation. Operation will not begin again in Flash mode until the Enable pin or Flash pin have been set Low and then High again.

Over-voltage Protection:

The OCP8111 has over voltage protection. If the output voltage rises above the 5.1V threshold, the over voltage protection shuts off all of the output switches to prevent the output voltage from rising further. When the output decreases below 5.1V, the device resumes normal operation.

Over-current Protection: The over current protection circuitry monitors the average current out of the VOUT pin. If the average output current exceeds approximately 1.6 Amps, then the over current protection circuitry shuts off the output switches to protect the chip.

Brightness Control using PWM:

Dimming control can be achieved by applying a PWM control signal to the EN pin. The brightness of the white LEDs is controlled by increasing and decreasing the duty cycle of the PWM signal. While the operating frequency range of the PWM control is from 60Hz to 700Hz, the recommended maximum brightness frequency range of the PWM signal is from 60Hz to 200Hz. A repetition rate of at least 60Hz is required to prevent flicker.

Over-temperature Protection:

When the temperature of the OCP8111 rises above 145℃, the over temperature protection circuitry turns off the output switches to prevent damage to the device. If the temperature drops back down below 135 degrees Celsius, the part automatically recovers and executes a soft start cycle.

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OCP8111

󰂄 Ordering Information

OCP8111XXX

Packing： Temperature Grade：Package：

A:Tape&Reel D: -40°C~85°CV:DFN3030-10L

Part Number

Driver Capability

Package Type

Package Qty 13-in reel 3000pcs/reel

Temperature -40～85℃

Eco Plan Green

1.0A Buck/Boost Charge Pump LED Driver

Lead Cu

OCP8111VAD 1.0A DFN3030-10L

󰂄 Marking Information

DFN3030-10L

Pin 1 Sign

OCSXXXXXXXXLogoPart Number

Internal codePage10 - 12 Ver. 1.4 Feb.04, 2013

OCP8111

󰂄 Package Information

DFN3030-10L:

1.0A Buck/Boost Charge Pump LED Driver

Symbol

Dimensions In Millimeters Min.

Nom.

Max.

Dimensions In Inches Min.

Nom.

Max.

A 0.70 0.75 0.80 0.027 0.029 0.031 A1 0.00 - 0.05 0.00 - 0.002 A3

0.20 REF

0.008 REF

D 2.95 3.00 3.05 0.116 0.118 0.120 E 2.95 3.00 3.05 0.116 0.118 0.120 b 0.18 0.25 0.30 0.007 0.010 0.012 L 0.30 0.40 0.50 0.011 0.016 0.020 D2 2.30 2.45 2.55 0.091 0.096 0.100 E2 1.50 1.65 1.75 0.059 0.0 0.069 e

0.50 BSC

0.020 BSC

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OCP8111

1.0A Buck/Boost Charge Pump LED Driver

󰂄 Packing Information

Package Type

Carrier Width(W)

PDPitch(P) Reel Size(D) 330±1 mm

WPacking Minimum

3000pcs

DFN3030-10L 12.0±0.1 mm 4.0±0.1 mm Note: Carrier Tape Dimension, Reel Size and Packing Minimum

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