CAT3637
6-Channel Programmable
High Efficiency LED Driver
Description
The CAT3637 is a high efficiency fractional charge pump that can
drive up to six LEDs programmable by a 1−wire digital interface. The
inclusion of a 1.33x fractional charge pump mode increases device
efficiency by up to 10% over traditional 1.5x charge pumps with no
added external capacitors.
Low noise input ripple is achieved by operating at a constant
switching frequency which allows the use of small external ceramic
capacitors. The multi−fractional charge pump supports a wide range of
input voltages from 2.5 V to 5.5 V.
The EN/SET logic input functions as a chip enable and a digital
programming interface for setting the current in the LED channels.
The 1−wire pulse−programming interface supports 15 linear steps
from zero current to 30 mA full−brightness in 2 mA steps.
The device is available in a tiny 16−pad TQFN 3 x 3 mm package
with a maximum height of 0.8 mm.
ON Semiconductor’s 1.33x, charge pump switching architecture is
patented.
Features
http://onsemi.com
TQFN−16
HV3 SUFFIX
CASE 510AD
PIN CONNECTIONS
EN/SET
GND
NC
NC
LED6
LED5
LED4
LED3
1
C2−
C2+
C1−
C1+
•
•
•
•
•
•
•
•
•
•
•
•
High Efficiency 1.33x Charge Pump
Charge Pump: 1x, 1.33x, 1.5x, 2x
Drives 6 LEDs Between 30 mA and 0 mA Each
1−wire EZDimt Interface with 2 mA Step
Power Efficiency up to 92%
Low Noise Input Ripple in All Modes
“Zero” Current Shutdown Mode
Soft Start and Current Limiting
Short Circuit Protection
Thermal Shutdown Protection
Tiny 3 mm x 3 mm, 16−pad TQFN Package
These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
LCD Display Backlight
Cellular Phones
Digital Still Cameras
Handheld Devices
LED2
LED1
(Top View)
MARKING DIAGRAM
JAAM
AXXX
YWW
JAAM = CAT3637HV3−GT2
A = Assembly Location
XXX = Last Three Digits of Assembly Lot Number
Y = Production Year (Last Digit)
WW = Production Week (Two Digits)
Applications
•
•
•
•
ORDERING INFORMATION
Device
CAT3637HV3−GT2
(Note 1)
Package
TQFN−16
(Pb−Free)
Shipping
†
2000 /
Tape & Reel
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specifications
Brochure, BRD8011/D.
1. NiPdAu Plated Finish (RoHS−compliant).
©
Semiconductor Components Industries, LLC, 2014
August, 2014
−
Rev. 4
1
Publication Order Number:
CAT3637/D
VOUT
VIN
CAT3637
1
mF
V
IN
2.5 V
to
5.5 V
C
IN
1
mF
1
mF
V
OUT
C
OUT
1
mF
C1− C1+ C2− C2+
VIN
VOUT
CAT3637
EN/SET
GND
LED1
LED2
LED3
LED4
LED5
LED6
1−Wire
Programming
Figure 1. Typical Application Circuit
Table 1. ABSOLUTE MAXIMUM RATINGS
Parameter
VIN, LEDx, C1±, C2± voltage
VOUT Voltage
EN/SET Voltage
Storage Temperature Range
Junction Temperature Range (Note 2)
Lead Temperature
Rating
6
7
VIN + 0.7 V
−65
to +160
−40
to +150
300
Unit
V
V
V
_C
_C
_C
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality
should not be assumed, damage may occur and reliability may be affected.
Table 2. RECOMMENDED OPERATING CONDITIONS
Parameter
VIN
Ambient Temperature Range (Note 2)
I
LED
per LED pin
Total Output Current
Range
2.5 to 5.5
−40
to +85
0 to 30
0 to 180
Unit
V
_C
mA
mA
Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond
the Recommended Operating Ranges limits may affect device reliability.
2. Package thermal resistance is below 50°C/W when mounted on FR4 board.
http://onsemi.com
2
CAT3637
Table 3. ELECTRICAL OPERATING CHARACTERISTICS
(over recommended operating conditions unless specified otherwise) V
IN
= 3.6 V, EN = High, T
AMB
= 25°C
Symbol
I
Q
Quiescent Current
Name
Conditions
1x mode, V
IN
= 4.2 V
1.33x mode, V
IN
= 3.3 V
1.5x mode, V
IN
= 2.8 V
2x mode, V
IN
= 2.5 V
V
EN
= 0 V
2 mA
≤
I
LED
≤
30 mA
I
LED
*
I
LEDAVG
I
LEDAVG
1x mode, I
OUT
= 120 mA
1.33x mode, I
OUT
= 120 mA
1.5x mode, I
OUT
= 120 mA
2x mode, I
OUT
= 120 mA
1.33x and 2x mode
1.5x mode
V
OUT
< 0.5 V
0.6
0.8
±3
±1
0.5
3.5
3.5
6
0.8
1.1
80
150
V
IN
−
Highest LED V
F
V
OUT
> 1 V
400
120
450
100
1.3
0.4
150
20
2
1.1
1.4
Min
Typ
1.5
2.8
3.7
3.8
1
Max
Units
mA
I
QSHDN
I
LED−ACC
I
LED−DEV
R
OUT
Shutdown Current
LED Current Accuracy
LED Channel Matching
mA
%
%
Output Resistance (open loop)
W
F
OSC
I
SC_MAX
LED
TH
V
HYS
T
DF
I
IN_MAX
R
EN/DIM
V
HI
V
LO
T
SD
T
HYS
V
UVLO
Charge Pump Frequency
Output short circuit Current Limit
1x to 1.33x or 1.33x to 1.5x or
1.5x to 2x Transition Thresholds at any LEDx pin
1.33x to 1x Transition Hysteresis
Mode Transition Filter Delay
Input Current Limit
EN/DIM Pin
−
Internal Pull−down Resistor
−
Logic High Level
−
Logic Low Level
Thermal Shutdown
Thermal Hysteresis
Undervoltage lockout (UVLO) threshold
MHz
mA
mV
mV
ms
mA
kW
V
V
°C
°C
V
Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product
performance may not be indicated by the Electrical Characteristics if operated under different conditions.
NOTE: Typical application circuit with external components is shown on page 2.
http://onsemi.com
3
CAT3637
Table 4. RECOMMENDED EN/SET TIMING
(For 2.5
≤
V
IN
≤
5.5 V, over full ambient temperature range
−40°
to +85°C.)
Symbol
T
LO
T
HI
T
OFF
T
D
Name
EN/SET program low time
EN/SET program high time
EN/SET low time to shutdown
LED current settling time
T
HI
Conditions
Min
0.2
0.2
1.5
10
Typ
Max
100
Units
ms
ms
ms
ms
EN/SET
T
LO
T
D
LED
Current
Shutdown
0 mA
28 mA
6 mA
0 mA
30 mA
T
OFF
2 mA 4 mA
2 mA
Shutdown
Figure 2. EN/SET One Wire Addressable Timing Diagram
http://onsemi.com
4
CAT3637
TYPICAL PERFORMANCE CHARACTERISTICS
(V
IN
= 3.6 V, I
OUT
= 120 mA (6 LEDs at 20 mA), C
IN
= C
OUT
= C
1
= C
2
= 1
mF,
T
AMB
= 25°C unless otherwise specified.)
100
V
F
= 3.3 V
90
EFFICIENCY (%)
1x
80
70
60
50
40
1.33x
1.5x
EFFICIENCY (%)
2x
90
80
70
60
50
40
Traditional 1.5x
Charge Pump
4.2
4.0
3.8
3.6
3.4
3.2
3.0
100
V
F
= 3.3 V
V
F
= 3.0 V
4.5
4.0
3.5
3.0
2.5
2.0
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Figure 3. Efficiency vs. Input Voltage
10
LED CURRENT VARIATION (%)
6
4
2
0
−2
−4
−6
−8
−10
LED CURRENT VARIATION (%)
8
V
F
= 3.3 V
10
8
6
4
2
0
−2
−4
−6
−8
−10
−40
Figure 4. Efficiency vs. Li−Ion Voltage
5.5
5.0
4.5
4.0
3.5
3.0
2.5
−20
0
20
40
60
80
INPUT VOLTAGE (V)
TEMPERATURE (°C)
Figure 5. LED Current Change vs. Input
Voltage
6
QUIESCENT CURRENT (mA)
V
F
= 3.3 V
5
4
3
2
1
0
5.5
5.0
4.5
4.0
3.5
3.0
Figure 6. LED Current Change vs.
Temperature
2.5
2.0
INPUT VOLTAGE (V)
Figure 7. Quiescent Current vs. Input Voltage
http://onsemi.com
5
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
