View CM9320-01DE_1227131.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

PRELIMINARY CM9320 Asymmetrical High Efficiency Two Channel Boost LED Driver
Features
* * 2.7V to 6V input voltage range Up to 85% typical efficiency even for asymmetrical channel loads in terms of LED number, LED current and LED dropout Excellent 5 series x 2 parallel WLED drive capability Up to 100 mA/19V output current/voltage Independent current setting using an external low power resistor for each channel (no ballast resistors) No external frequency compensation needed Low (<1%) LED output voltage and current ripple Input undervoltage lockout and output over-voltage protection 1 MHz fixed switching frequency (0.5 MHz option available) Uses small inductor and ceramic capacitors Integrated low ON-Resistance (0.3 ) N-Chann el MOSFET switch Disconnects LEDs during shutdown Low profile TDFN-10 package Optional RoHS compliant lead free packaging
Product Description
The CM9320 is a high frequency, two-channel inductorbased PWM boost regulator specifically designed for constant current white LED drive applications. With a maximum 100 mA/19V output capability, the circuit can drive up to 10 WLEDs (5 series x 2 parallel) allowing up to 35 mA per channel. With a typical input voltage range from 2.7V to 6.0V, it can be operated from a single cell Li-Ion battery. The proprietary FlexBoostTM architecture (patent pending) provides high efficiency (typical 85%) for a wide input voltage range, even for asymmetrical channel loads in terms of LED number, LED current and LED type. The maximum LED current for each channel is independently programmed with external low-power resistors (no ballast resistors needed). A 1 MHz constant frequency PWM saves board space, allowing small, low-cost external components, permitting designers to avoid sensitive IF bands in RF applications. The output over-voltage protection circuit prevents damage in case of a high impedance output (e.g. faulty LED). The controlled current limit circuit prevents large inductor current spikes, even at start-up. To avoid possible leakage currents, the EN control pin disconnects the LEDs from ground during shutdown. The CM9320 is available in a compact TDFN-10 package. It can operate over the industrial temperature range of 40C to 85C.
* * * * * * * * * * * *
Applications
* * * * * * Drives white LEDs for backlighting color LCD Cell phones MP3 players, PDA, GPS Digital Still Cameras LED flashlights Handheld devices
Typical Application
VIN 2.7V to 6.0V 10 uF/10V
off on (by default)
L1 Enable 4.7 uH
D1 1A, 20V
VOUT COUT 1 uF/16V
CIN
RSET1 22K
1 2
ISET1 LED1 NC ISET2 LED2
EN VOUT
10 Channel 9 CH1 CH2
3 RSET2 22K 5 4
PhotonICTM
CM9320
SW GND VIN
8 7
6
(c) 2006 California Micro Devices Corp. All rights reserved. 05/08/06
490 N. McCarthy Blvd., Milpitas, CA 95035-5112
l
Tel: 408.263.3214
l
Fax: 408.263.7846
l
www.cmd.com
1
PRELIMINARY CM9320
Package Pinout
PACKAGE / PINOUT DIAGRAM
TOP VIEW
(Pins Down View)
10 9 8 7 6
BOTTOM VIEW
(Pins Up View)
12345
Pin 1 Marking
CMxxx xxxxxx
GND PAD
12345
10 9 8 7 6
CM9320-01DE 10 Lead TDFN Package
Note: This drawing is not to scale.
Ordering Information
PART NUMBERING INFORMATION
Lead Free Finish Pins 10 Package TDFN Ordering Part Number1 CM9320-01DE Part Marking
Note 1: Parts are shipped in Tape & Reel form unless otherwise specified.
Specifications
ABSOLUTE MAXIMUM RATINGS
PARAMETER ESD Protection (HBM) VIN to GND Pin Voltages VOUT, SW to GND LED1, LED2 to GND ISET1, ISET2 to GND Storage Temperature Range Operating Temperature Range Lead Temperature (Soldering, 10s) RATING 2 [GND - 0.3] to +6.0 20 20 [GND - 0.3] to +5.0 -65 to +150 -40 to +85 300 UNITS kV V V V V C C C
(c) 2006 California Micro Devices Corp. All rights reserved.
2
490 N. McCarthy Blvd., Milpitas, CA 95035-5112
l
Tel: 408.263.3214
l
Fax: 408.263.7846
l
www.cmd.com
05/08/06
PRELIMINARY CM9320
Specifications (cont'd)
ELECTRICAL OPERATING CHARACTERISTICS (SEE NOTE 1)
SYMBOL PARAMETER CONDITIONS MIN TYP VIN = 3.6V; CIN = 10F, COUT = 1F, L1 = 4.7H, interleave mode, TA = 25C (unless otherwise specified) VIN IQ VUVLO VOVP ISD VEN Channel 1 ILED1 Input Voltage Range Quiescent Current Undervoltage Lockout Output Overvoltage Protection Shutdown Current Device Enable Threshold ILED < 0.6mA (each channel), nonswitching VIN Rising VOUT Rising VEN = 0V Device ON (by default) Device OFF VIN = 3.0V to 6.0V, RSET1(k) 4 WLED VIN = 2.7V to 6.0V Standard load (Note 3) VIN = 3.0V to 6.0V, RSET2(k) 4 WLED VIN = 2.7V to 6.0V Standard load (Note 3) VIN = 3.0V to 6.0V Each Channel VIN = 3.0V to 6.0V ILED 1,2 = 2mA to ILED MAX VIN = 2.7V to 6.0V, ILED 1,2 = 2mA to ILED MAX Standard Load (Note 3) ISW = 0.8A, VGS = 15V Standard Load (Note 3) Standard Load (Note 3) ILED 1,2 = 20mA, 4WLED+1W 1% RSET Accuracy, Each Channel Standard Load (Note 3) All Channels VIN = 2.7V to 6.0V 0 0.8 1.0 80 VIN 5 50 300 85 0.5 835 3 0.2 0.6 1.2 500 20 95 2 1 0.80 1 1.0 0.2 2 1 0.80 450 --------------R SET2 30 5 V %/V mA V % mVpp m % A mW % mApp mA MHz 450 --------------R SET1 35 5 V mA 2.7 1.2 2.0 19.0 2.2 19.5 10 MAX 6.0 2.0 2.4 20.0 15 UNITS V mA V V A V V mA
LED Current (Note 1) Number of LEDs (Note 2)
VLED1 Channel 2 ILED2
Voltage on LED1 Pin LED Current (Note 1) Number of LEDs (Note 2)
VLED2
Voltage on LED2 Pin
Boost Circuit (Note 3) ILED / ILED VIN Line Regulation IOUT VOUT D VOUTR RDSON Eff ISW PIN Control ILED acc ILEDR ILEDNL fs Boost Output Current Boost Output Voltage Duty Cycle Range Output Voltage Ripple MOSFET ON Resistance Efficiency Switch Peak Current Input Power Channel Current Matching (Note 4) LED Current Ripple No-Load Mode (Note 5) Switching Frequency
(c) 2006 California Micro Devices Corp. All rights reserved. 05/08/06
490 N. McCarthy Blvd., Milpitas, CA 95035-5112
l
Tel: 408.263.3214
l
Fax: 408.263.7846
l
www.cmd.com
3
PRELIMINARY CM9320
Specifications (cont'd)
ELECTRICAL OPERATING CHARACTERISTICS (SEE NOTE 1)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VIN = 3.6V; CIN = 10F, COUT = 1F, L1 = 4.7H, non-interleave mode (Note 6), TA = 25C (unless otherwise specified) ILED LED Current Line Regulation @ High Load VIN = 3.0V to 6.0V, RSET(k) L = 4.7H, VIN = 3.0V to 5.5V 4W+4W, 40mA+40mA L = 10H, VIN = 3.0V to 5.5V 4W+4W, 50mA+40mA L = 10H, VIN = 2.8V to 5.5V 3W+4W, 60mA+40mA ILED 1,2 = 20mA, 4WLED+1W
I LED ( mA ) 450 = --------------------R
2
730-----------R SET 1 3 1 730
IMAX
mA %/V %/V %/V mW
ILED / VIN
PIN
Input Power
Note 1: ILED is the average PWM current through the LED string with internal 2/3 duty cycle and a 6 ms period. The following formula must be used to calculate the LED current:
SET ( k )
Note 2: For lower LED forward voltage the number of LEDs can be increased up to the maximum output voltage limit. Note 3: Standard Load is a 4 series x 2 parallel configuration set for IsetLED = 20 mA each channel (RSET1,2 = 22 k). Generally, a "4W+1W" like formula denotes the WLED number of each channel, i.e. CH1+CH2 configurations. Note 4: [ILED(set) - ILED(effective)] / ILED(set) for each channel. Note 5: A LED current value below 0.6 mA for each channel set the circuit in No-load mode; all channels and MOSFET switch are in shutdown and DC circuit current consumption is limited to 1 mA (see quiescent current). Note 6: For non-interleave mode, all parameters have the same min/typ/max interleave mode values, unless otherwise specified.
(c) 2006 California Micro Devices Corp. All rights reserved.
4
490 N. McCarthy Blvd., Milpitas, CA 95035-5112
l
Tel: 408.263.3214
l
Fax: 408.263.7846
l
www.cmd.com
05/08/06
PRELIMINARY CM9320
Typical Performance Curves
ILED vs. VIN
21 .2 21 .0 20.8 20.6 1 20
ILED vs. VIN (high currents)
ILED1
10 1
L=10uH, 3W+4W, 60mA+40mA
ILED1+ILED2 (mA)
1 00
ILED (mA)
20.4 20.2 20.0 1 9.8 1 9.6 1 9.4 1 9.2 1 9.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
L=10uH, 4W+4W, 50mA+40mA
90 80 70 60 50 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
ILED2
L=4.7uH, 4W+4W, 40mA+40mA
L = 4.7uH 4 WLED/ch TA = 25 C
No-Interleave TA = 25 C
VIN (V)
VIN (V)
EFFICIENCY v.s VIN
90 90
EFFICIENCY vs. ILED
Vin=5.6V
85
4.2V 3.6V 3.0V 2.7V
Efficiency (%)
Efficiency (%)
ILED1,2 = 20mA L = 4.7uH 4 WLED/ch
85
80
75
80
70
65
L = 4.7uH 4 WLED/ch TA = 25 C
0 5 1 0 1 5 20 25 30 35
75 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
60
VIN (V)
ILED (m A)
EFFICIENCY vs. INDUCTOR
90
EFFICIENCY vs. STRING CONFIGURATION
90 88 86
L=4.7uH L=3.3uH L=2.7uH L=1.5uH
ILED=20mA+20mA
85
Efficiency (%)
Efficiency (%)
80
84 82 80 78
ILED=5mA+20mA ILED=20mA+5mA
75
L=10uH L=15uH ILED1,2 = 20 mA 4 WLED/ch TA = 25 C
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
70
76 74 2.0 2.5 3.0 3.5 4.0 4.5
L = 4.7uH CH1,2 = 4W+3W TA = 25 C
5.0 5.5 6.0
65
VIN (V)
(c) 2006 California Micro Devices Corp. All rights reserved. 05/08/06
VIN (V)
490 N. McCarthy Blvd., Milpitas, CA 95035-5112
l
Tel: 408.263.3214
l
Fax: 408.263.7846
l
www.cmd.com
5
PRELIMINARY CM9320
Functional Block Diagram
V IN
UVLO BIAS BG OSC PMW LOGIC
OVP D4
V OU T SW
Q4 R
EN
ENABLE D1
L E D1
Q1
ISET1
CONTROL
ISET2
D2
L E D2
Q2
CM9320
G ND
Pin Descriptions
PIN DESCRIPTIONS
LEAD(s) 1 NAME ISET1 DESCRIPTION Channel 1 LED current set pin. Between this pin and GND connect the RSET1 resistor, calculated as follows: 450 R SET1 ( k ) = ---------------------------I LED1 ( mA ) where ILED1 is the DC LED current in channel 1. 2 3 4 LED1 NC ISET2 Pin to cathode of channel 1 LED string. Not internally connected. For better heat flow, connect to GND. Channel 2 LED current set pin. Between this pin and GND connect the RSET2 resistor, calculated as follows: 450 R SET2 ( k ) = ---------------------------I LED2 ( mA ) where ILED2 is the DC LED current in channel 2. 5 6 7 8 9 LED2 VIN GND SW VOUT Pin to cathode of channel 2 LED string. Input supply voltage pin. Bypass with a 10F or larger ceramic capacitor to ground. Ground terminal pin. Switching node. Internally connected to the drain of the integrated switch. Output voltage pin, which connects to the anodes of all LEDs. Bypass with a 1.0F or greater ceramic capacitor to ground for low output ripple voltage.
(c) 2006 California Micro Devices Corp. All rights reserved.
6
490 N. McCarthy Blvd., Milpitas, CA 95035-5112
l
Tel: 408.263.3214
l
Fax: 408.263.7846
l
www.cmd.com
05/08/06
PRELIMINARY CM9320
Pin Descriptions (cont'd)
PIN DESCRIPTIONS
10 EPad EN GND Enable pin. The circuit is ON when VEN is above 1.0V. The circuit is OFF when VEN is below 0.2V. Active High (ON) by default. Ground (backside exposed pad).
Application Information
The CM9320 is a high efficiency, constant frequency current regulating boost driver ideally suited for driving white LEDs to backlight LCD color displays and a camera flash in Li-ion powered portable devices. The CM9320 is the perfect driver for portable applications such as cellular phones, digital still cameras, PDAs and any application where small space, compact overall size and low system cost are critical. With a maximum 100 mA/19V output capability, the circuit can drive up to 10 WLEDs (5 series x 2 parallel), allowing up to 35 mA per channel. It includes a switch and an internally compensated loop for regulating the current into the LEDs. The CM9320 delivers a constant current to series-connected LEDs, ensuring uniform brightness and color purity regardless of any LED forward voltage variations. The proprietary design architecture allows asymmetrical loading on each channel and maintains high efficiency (typ 85%) at low VIN resulting in longer battery life, and cool, reliable operation when an adapter is supplying high VIN. The maximum LED current for each channel is independently programmed with external low power resistors avoiding the need for ballast resistors. An 1MHz constant frequency PWM scheme saves board space with the use of small, low cost external components, allowing designers to avoid sensitive IF bands in RF applications. The circuit operates with low value inductors and low value output ceramic capacitors, keeping voltage and current ripple in the 1% range. The output over-voltage protection circuit prevents damage in case of a high impedance output (e.g. faulty LED). The controlled current limit circuit limit prevents large inductor current spikes, even at start-up. To avoid possible leakage currents, the EN control pin disconnects the LEDs from ground during shutdown.
CM9320 Operation
When a voltage that exceeds the undervoltage lockout threshold (UVLO) is applied to the VIN pin, the CM9320 initiates a softstart which limits the inrush current while the output capacitors are charged. Following softstart, the CM9320's internal NMOS drives an external inductor and Schottky diode that delivers the inductor's stored energy to the load. Setting the LED Current The output current is set by the value of the RSET connected between the ISET pin and GND, according to the equations: (a) Interleave
450 R SET ( k ) = ------------------------I LED ( mA ) 730 R SET ( k ) = ------------------------I LED ( mA )
(b) Non-interleave
PWM Brightness Control The brightness WLEDs level can be continuously controlled for each channel using a PWM signal in 1-50 KHz range (recommended value is 10 kHz). As an example, the PWM signal can be applied directly through RSET resistor for negative slope or by using a
(c) 2006 California Micro Devices Corp. All rights reserved. 05/08/06
490 N. McCarthy Blvd., Milpitas, CA 95035-5112
l
Tel: 408.263.3214
l
Fax: 408.263.7846
l
www.cmd.com
7
PRELIMINARY CM9320
Application Information (cont'd)
switch transistor for positive slope. See Figure 1 for different brightness control methods and results. selected based on the required load power and the minimum input voltage. The saturation current rating should be chosen well above the steady state peak inductor current. At minimum VIN and full duty cycle (worse case), this is approximately:
1V IN ( MIN ) x t ON 3V x 0.8 x --------------1MHz I PEAK -------------------------------------- ------------------------------------------- 0.5A L 4.7H
PWM signal
RSET1 22k RSET2 ISET2 91k CM9320 ISET1
Diode Selection The low forward voltage and fast switching time make Schottky diodes the choice for high efficiency operation. Make sure the diode has a reverse voltage rating greater than the maximum output voltage. The diode conducts only when the power switch is on, so a peak current rating above 1A should be sufficient for a typical design. Capacitor Selection For proper performance, use surface-mount, low ESR ceramic capacitors for CIN and COUT. X7R or X5R ceramic dielectric provides good stability over the operating temperature and voltage range. In most LED applications, high frequency output ripple is not a concern because it will not cause intensity variations that are visible to the human eye. For such applications, when low ripple is needed, a 22F input capacitor and/or 2.2 F output capacitor are recommended.
REF DES CIN COUT L1
(a) Schematic
25
20
ILED1 negative slope
ILED (mA)
1 5
1 0
ILED2 positive slope
5
0 0 1 0 20 30 40 50 60 70 80 90 1 00
DUTY (%)
(b) Brightness curves
Figure 1. Brightness Control Using Different Methods Inductor Selection The inductor is used to store energy in a boost converter. The amount of energy stored in the inductor and transferred to the load is controlled by the PWM. The inductor is operated in the discontinuous conduction mode, and to assume proper operation, the inductor value must be limited to a maximum value. An inductor with low series resistance (DCR) decreases power losses and increases efficiency. The core material should be capable of operating at I MHz with minimum core losses. An inductance of 4.7H is optimal for most applications, but low DCR inductor values in 1.5-15uH range are also recommended for high efficiency applications. To ensure proper operation of the current regulator over a wide range of conditions, the inductor should be
(c) 2006 California Micro Devices Corp. All rights reserved.
DESCRIPTION Capacitor, 10F, 10V, Ceramic, 1206 Capacitor, 1F, 16V, Ceramic, 0805 Inductor, 4.7H, 1A, Low DCR
D1
Schottky Diode, 1A, 20V, SMD
SOURCE Murata, GRM319R61A106KE19D Vishay, VJ1206G106KXQ Murata, GRM188R61C105KA93D TDK, C2012X5R1C105K Coilcraft, LP06013-472ML TMP Electronics Co., SPC-03802-4R7 CHILISIN, SCD03015-4R7 SUMIDA, CDH3D13/S4R7 IR, MBRS120 CHENMKO, SSM5817S
Input Filter If CM9320 is more than 4" from main power supply point, use an input RC filter to avoid high ripple and input transients to the circuit input pin (see Figure 2).
Fax: 408.263.7846 www.cmd.com
8
490 N. McCarthy Blvd., Milpitas, CA 95035-5112
l
Tel: 408.263.3214
l
l
05/08/06
PRELIMINARY CM9320
Application Information (cont'd)
In this case, because of small input ripple, the efficiency is about 2% higher.
to VIN
CM9320
GND VIN 7 6 CF 0.1 uF/10V RF 100
Figure 2. Input Filter Solution
Layout Guide
Components should be placed as close as practical to the IC to assure good performance. The input and output capacitors should be close, with minimum trace resistance and inductance. Reflected input ripple depends on the impedance of the VIN source, such as the PCB traces and the Li-ion battery, which have elevated impedance at higher frequencies. The input capacitor located near the converter input reduces this source impedance and ripple. Any ESR from the capacitor will result in steps and spikes in the ripple waveform, and possibly produce EMI. Route any noise sensitive traces away from the switching power components. Place the inductor and diode as close as possible to the SW pin to prevent noise emissions. The ground connections for RSET(1,2) resistors should be kept separate from the high power grounds and connect directly to the ground pin to assure accurate current and voltage settings. For better heat flow, connect all NC pins to GND plane. Also connect the thermal landing to the bottom ground plane with thermal vias.
Figure 3. Example CM9320 PC Layout and Component Placement for Standard Application
(c) 2006 California Micro Devices Corp. All rights reserved. 05/08/06
490 N. McCarthy Blvd., Milpitas, CA 95035-5112
l
Tel: 408.263.3214
l
Fax: 408.263.7846
l
www.cmd.com
9
PRELIMINARY CM9320
Mechanical Details
TDFN-10 Mechanical Specifications Dimensions for the CM9320 packaged in a 10-lead TDFN package are presented below. For complete information on the TDFN-10, see the California Micro Devices TDFN Package Information document. Mechanical Package Diagrams
D
10 9 8 7 6
PACKAGE DIMENSIONS
Package JEDEC No. Leads Dim. A A1 A2 A3 b D D2 E E2 e K L # per tube # per tape and reel 1.30 0.20 1.40 2.20 0.18 Millimeters Min 0.70 0.00 0.45 Nom 0.75 0.02 0.55 0.20 0.25 3.00 2.30 3.00 1.50 0.50 1.50 0.30 1.70 0.40 0.051 0.008 NA 3000 pieces 1.60 0.055 2.40 0.087 0.30 0.007 Max 0.80 0.05 0.65 Min 0.028 0.000 0.018 TDFN MO-229 (Var. WEED-3)= 10 Inches Nom 0.030 0.001 0.022 0.008 0.010 0.118 0.091 0.118 0.060 0.020 0.060 0.012 0.067 0.016 Pin 1 ID
C0.35
E
Pin 1 Marking
Max 0.031 0.002 0.026
0.10 C
12345 TOP VIEW
0.012
0.08 C
0.094
A1
SIDE VIEW
A
A3 A2
0.063
1
2
3
4
5
GND PAD
Controlling dimension: millimeters
D2 L
=This package is compliant with JEDEC standard MO-229, variation WEED-3 with exception of the "D2" and "E2" dimensions as called out in the table above.
K e
10
9
8
7
6
b
8X
E2
BOTTOM VIEW
0.10
M
CAB
Package Dimensions for 10-Lead TDFN
(c) 2006 California Micro Devices Corp. All rights reserved.
10 490 N. McCarthy Blvd., Milpitas, CA 95035-5112
l
Tel: 408.263.3214
l
Fax: 408.263.7846
l
www.cmd.com
05/08/06

▲Up To Search▲

Price & Availability of CM9320-01DE

	To Download CM9320-01DE Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .