19-3689; Rev 0; 5/05
KIT
ATION
EVALU
BLE
AVAILA
125mA 1x/1.5x Charge Pumps for 5 White LEDs
in 3mm x 3mm TDFN
General Description
The MAX8630Y/MAX8630Z charge pumps drive up to 5
white LEDs with regulated constant current up to 125mA
total. By utilizing adaptive 1x/1.5x charge-pump modes
and very low-dropout current regulators, they achieve
high efficiency over the full 1-cell Li+ battery input volt-
age range. The 1MHz fixed-frequency switching allows
for tiny external components, and the regulation scheme
is optimized to ensure low EMI and low input ripple. An
integrated derating function protects the LEDs from
overheating during high ambient temperatures.
The MAX8630Y/MAX8630Z are factory trimmed for full-
scale LED current options of 15mA, 18mA, 20mA, and
25mA. The MAX8630Z uses two enable inputs (ENM for
3 main LEDs and ENS for 2 sub LEDs) for simple on/off
control and single-wire, serial-pulse dimming in 32 linear
steps. The MAX8630Y uses a single direct PWM input
(PWM) to control all 5 LEDs with DC current proportional
to the PWM duty cycle. If both ENM and ENS (or PWM)
are kept low for more than 2ms, the MAX8630_ enters
shutdown. The MAX8630Y/MAX8630Z are available in a
14-pin, 3mm x 3mm TDFN package (0.8mm max
height).
Features
♦
93% Max/85% Avg. Efficiency (P
LED
/P
BATT
) Over
Li+ Battery Discharge
♦
1% LED Current Accuracy
♦
125mA Total Drive Capability
♦
Adaptive 1x/1.5x Mode Switchover
♦
Single-Wire, Serial-Pulse Dimming (MAX8630Z)
Independent On/Off/Dimming for Main and Sub
Linear—Full, 31/32nd, 30/32nd, … 1/32nd
♦
Direct-PWM Dimming (MAX8630Y)
♦
15, 18, 20, and 25mA Full-Scale Versions
♦
Low 0.1µA Shutdown Current
♦
Soft-Start Eliminates Inrush Current
♦
Output Overvoltage Protection
♦
Thermal-Derating Function Protects LEDs
♦
14-Pin, 3mm x 3mm TDFN Package
MAX8630Y/MAX8630Z
Applications
Display Backlight (Up to 5 LEDs)
Main (3 LEDs) + Sub (2 LEDs) Displays
Cell Phones and Smartphones
PDAs, Digital Cameras, and Camcorders
Selector Guide appears at end of data sheet.
PART
Ordering Information
TEMP RANGE
PIN-
PACKAGE
TOP
MARK
14 TDFN
MAX8630YETD15
-40°C to +85°C 3mm x 3mm
AAS
(T1433-2)
Ordering Information continued at end of data sheet.
Pin Configuration
ENS (PWM)
8
7
OUT
TOP VIEW
LED1
LED2
LED3
LED4
LED5
10
5
C2P
1µF
INPUT
2.7V TO 5.5V
1µF
GND
MAX8630Z
LED1
LED2
ENM
LED3
SUB
LED4
ENS
C2P
C2N
LED5
14
C1P
IN
C1N
OUT
OUTPUT
1µF
MAIN
13
12
11
ENABLE MAIN
ON/OFF AND
DIMMING
ENABLE SUB
ON/OFF AND
DIMMING
MAX8630Y
MAX8630Z
1
GND
2
C1N
3
IN
4
C2N
1µF
( ) ARE FOR MAX8630Y
TDFN
3mm
×
3mm
________________________________________________________________
Maxim Integrated Products
C1P
ENM (CPWM)
9
6
Typical Operating Circuit
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
125mA 1x/1.5x Charge Pumps for 5 White LEDs
in 3mm x 3mm TDFN
MAX8630Y/MAX8630Z
ABSOLUTE MAXIMUM RATINGS
IN, OUT to GND.....................................................-0.3V to +6.0V
C1N, C2N, ENM, CPWM, ENS,
PWM to GND ............................................-0.3V to (V
IN
+ 0.3V)
LED_ to GND ............................................-0.3V to (V
OUT
+ 0.3V)
C1P, C2P to GND ...-0.3V to greater of (V
OUT
+ 1V) or (V
IN
+ 1V)
OUT Short Circuit to GND ..........................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
14-Pin TDFN 3mm x 3mm
(derate 18.2mW/°C above +70°C) .............................1454mW
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
IN
= 3.6V, V
GND
= 0V, EN_ (PWM) = IN, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
IN Operating Voltage
Undervoltage-Lockout Threshold
Undervoltage-Lockout Hysteresis
Output Overvoltage Protection
Threshold
No-Load Supply Current
Shutdown Supply Current
Soft-Start Time (t
SOFT-START
)
MAX8630_ETD15
Full-Scale LED Current
MAX8630_ETD18
MAX8630_ETD20
MAX8630_ETD25
Full-Scale LED Current Accuracy
Derating Function Start
Temperature
Derating Function Slope
LED_ Dropout Voltage
1x to 1.5x Mode Transition
Threshold
Input Voltage Mode Transition
Hysteresis
1.5x Mode Regulation Voltage
OUT Pulldown Resistance in
Shutdown
Minimum of V
LED_
ENM = ENS (PWM) = GND
T
A
= +40°C to +85°C
100% LED setting (Note 2)
V
LED_
falling
T
A
= +25°C
T
A
= -40°C to derating function start temperature
-1
-3.5
V
OUT
rising, any LED_ = GND
1/32nd setting, 1.5x mode
1/32nd setting, 1x mode
ENM = ENS (PWM) = GND
T
A
= +25°C
T
A
= +85°C
V
IN
rising or falling
CONDITIONS
MIN
2.7
2.20
2.45
100
5
1.4
0.35
0.01
0.1
2
15
18
20
25
±0.3
±0.3
40
-1.67
40
88
70
122
5
75
+1
+3.5
%
°C
%/°C
mV
mV
mV
mV
kΩ
mA
2
TYP
MAX
5.5
2.65
UNITS
V
V
mV
V
mA
µA
ms
2
_______________________________________________________________________________________
125mA 1x/1.5x Charge Pumps for 5 White LEDs
in 3mm x 3mm TDFN
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 3.6V, V
GND
= 0V, EN_ (PWM) = IN, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Open-Loop OUT Resistance
Maximum OUT Current
OUT Short-Circuit Current Limit
Switching Frequency
Direct-PWM Dimming Filter
Corner Frequency (MAX8630Y)
EN_ (PWM) High Voltage
EN_ (PWM) Low Voltage
EN_ (PWM) Minimum Input
Slew Rate
EN_ (PWM) Input Current
EN_ (PWM) Low Shutdown Delay
(t
SHDN
)
EN_ t
LO
(See Figure 4)
EN_ t
HI
(See Figure 4)
Initial EN_ t
HI
(See Figure 4)
Thermal Shutdown
Thermal-Shutdown Hysteresis
First EN_ (PWM) high pulse
C
CPWM
= 0.1µF, (PWM frequency of 900Hz to 100kHz
recommended)
V
IN
= 2.7V to 5.5V
V
IN
= 2.7V to 5.5V
V
IN
= 2.7V to 5.5V (recommended minimum slew rate)
V
EN_ (PWM)
= 0V or 5.5V
T
A
= +25°C
T
A
= +85°C
1
0.5
0.5
50
+160
20
1
0.01
0.1
2
4
500.0
1
1.4
0.4
CONDITIONS
1x mode, (V
IN
- V
OUT
) / I
OUT
1.5x mode, (1.5V
IN
- V
OUT
) / I
OUT
V
IN
≥
3.2V, V
OUT
= 3.9V
V
OUT
< 1.25V
125
57
1
10
MIN
TYP
0.8
3.2
MAX
1.5
7.2
UNITS
Ω
mA
mA
MHz
Hz
V
V
V/µs
µA
ms
µs
µs
µs
°C
°C
MAX8630Y/MAX8630Z
Note 1:
Limits are 100% production tested at T
A
= +25°C. Limits over the operating temperature range are guaranteed by design.
Note 2:
Dropout voltage is defined as the LED_ to GND voltage at which current into LED_ drops 10% from the value at V
LED_
= 0.2V.
Typical Operating Characteristics
(V
IN
= 3.6V, ENM = ENS = IN, T
A
= +25°C, unless otherwise noted.)
EFFICIENCY vs. INPUT VOLTAGE
DRIVING 5 LEDs
MAX8630Y/Z toc01
INPUT CURRENT vs. INPUT VOLTAGE
DRIVING 5 LEDs
MAX8630Y/Z toc02
INPUT CURRENT vs. INPUT VOLTAGE
DRIVING 3 MAIN LEDs
V
IN
FALLING
140
INPUT CURRENT (mA)
120
100
80
60
40
I
LED
= 1.875mA
20
0
I
LED
= 8.125mA
I
LED
= 20mA
MAX8630Y/Z toc03
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
2.7
3.0
3.3
3.6
3.9
V
IN
FALLING
I
LED
= 8.125mA
I
LED
= 1.875mA
I
LED
= 20mA
160
V
IN
FALLING
140
INPUT CURRENT (mA)
120
100
I
LED
= 8.125mA
80
60
40
20
0
I
LED
= 1.875mA
I
LED
= 20mA
160
4.2
2.7
3.0
3.3
3.6
3.9
4.2
2.7
3.0
3.3
3.6
3.9
4.2
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
_______________________________________________________________________________________
3
125mA 1x/1.5x Charge Pumps for 5 White LEDs
in 3mm x 3mm TDFN
MAX8630Y/MAX8630Z
Typical Operating Characteristics (continued)
(V
IN
= 3.6V, ENM = ENS = IN, T
A
= +25°C, unless otherwise noted.)
INPUT RIPPLE VOLTAGE vs. SUPPLY
VOLTAGE DRIVING 5 WHITE LEDs
MAX8630Y/Z toc04
INPUT CURRENT vs. INPUT VOLTAGE
DRIVING 2 SUB LEDs
160
V
IN
FALLING
140
INPUT CURRENT (mA)
120
100
80
60
I
LED
= 8.125mA
40
20
0
2.7
3.0
3.3
3.6
3.9
4.2
INPUT VOLTAGE (V)
I
LED
= 1.875mA
I
LED
= 20mA
140
LED CURRENT MATCHING vs. INPUT
VOLTAGE (25mA/LED)
MAX8630Y/Z toc05
20mA/LED
INPUT RIPPLE VOLTAGE (mV
P-P
)
120
100
80
60
40
20
0
2.7
3.2
3.7
2mA/LED
15mA/LED
8mA/LED
27
26
LED CURRENT (mA)
25
24
23
22
21
20
4.2
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
LED CURRENT MATCHING vs. INPUT
VOLTAGE (2.5mA/LED)
MAX8630Y/Z toc07
OUTPUT CURRENT vs. TEMPERATURE
(5 LEDs AT 25mA EACH)
MAX8630Y/Z toc08
2.80
2.70
2.60
LED CURRENT (mA)
2.50
2.40
2.30
2.20
2.10
2.00
2.7
3.1
3.5
3.9
4.3
4.7
5.1
140
120
OUTPUT CURRENT (mA)
100
80
60
40
20
0
TEMPERATURE
DERATING
5.5
-40
-15
10
35
60
85
INPUT VOLTAGE (V)
TEMPERATURE (°C)
1x MODE OPERATING WAVEFORMS
(V
IN
= 4.0V)
MAX8630Y/Z toc09
1.5x MODE OPERATING WAVEFORMS
(V
IN
= 3.6V)
MAX8630Y/Z toc10
V
OUT
200mV/div
(AC-COUPLED)
V
OUT
200mV/div
(AC-COUPLED)
V
IN
200mV/div
(AC-COUPLED)
V
IN
I
IN
200mV/div
(AC-COUPLED)
100mA/div
I
IN
100mA/div
1µs/div
1µs/div
4
_______________________________________________________________________________________
MAX8630Y/Z toc06
28
125mA 1x/1.5x Charge Pumps for 5 White LEDs
in 3mm x 3mm TDFN
MAX8630Y/MAX8630Z
Typical Operating Characteristics (continued)
(V
IN
= 3.6V, ENM = ENS = IN, T
A
= +25°C, unless otherwise noted.)
STARTUP AND SHUTDOWN
MAX8630Y/Z toc11
MAIN STARTUP AND SHUTDOWN
WITH SUB ENABLED
MAX8630Y/Z toc12
5V/div
V
ENM
AND
V
ENS
2V/div
V
ENM
5V/div
2V/div
V
OUT
V
OUT
0
100mA/div
I
IN
0
100mA/div
I
OUT
1ms/div
0
100mA/div
0
100mA/div
0
I
IN
I
OUT
1ms/div
0
STARTUP AND DIMMING
MAX8630Y/Z toc13
LINE-TRANSIENT RESPONSE WITH MODE CHANGE
(V
IN
= 3.8V TO 3.2V TO 3.8V)
MAX8630Y/Z toc14
V
ENM
AND
V
ENS
5V/div
1V/div
V
IN
1V/div
V
OUT
V
OUT
500mV/div
3V
I
OUT
20mA/div
I
OUT
50mA/div
0
20ms/div
200µs/div
Pin Description
PIN
MAX8630Z
1
MAX8630Y
1
NAME
FUNCTION
Ground. Connect GND to system ground and the input bypass capacitor as
close to the IC as possible. Connect GND to the exposed pad directly under
the IC.
Transfer Capacitor 1 Negative Connection. Connect a 1µF ceramic capacitor
from C1P to C1N.
Supply Voltage Input. Connect a 1µF ceramic capacitor from IN to GND. The
input voltage range is 2.7V to 5.5V.
Transfer Capacitor 2 Negative Connection. Connect a 1µF ceramic capacitor
from C2P to C2N.
GND
2
3
4
2
3
4
C1N
IN
C2N
_______________________________________________________________________________________
5
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