GMT G5115

Global Mixed-mode Technology Inc.
G5115/G5117/G5119
High Efficiency, Constant Current Output for 4 Series LEDs Driver
Features
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General Description
Driving Up to 4 LEDs
Auto Trigger/Release OVP Function
(G5115/G5119)
Input Voltage Range: 1.7V ~ 6.5V
Precise Dimming Control Using PWM Signal
50µA No Switching Current
Internal 18V Switch With 0.8Ω Rds(on)
Soft Start Function Included
Up to 85% Efficiency
The G5115/G5117/G5119 are high efficiency boost
converters with constant current output that drives up to
4 white LEDs. The continuous LED current is set with
the FB pin regulated voltage across an external sense
resistor (Rs) connected from that pin to ground. A dimming PWM waveform to SHDN pin controls LED average current proportional to its duty makes the brightness of LEDs also proportional to the duty.
Low FB regulation voltage and low switch turned on
resistance result in high converting efficiency from wide
battery voltage range to high LED series voltage.
Applications
White LED Backlight Display for PDA
Pocket PC
Smart Phones
Handheld Devices
„ Cellular Phones
„
„
„
„
An over-voltage protection prevents device damage
while LEDs is open. It is easy to release protection
state by just put the load path closed.
Ordering Information
ORDER NUMBER
ORDER NUMBER
(Pb free)
MARKING
TEMP. RANGE
PACKAGE
G5115T1U
G5115T1Uf
5115X
-40°C ~ +85°C
SOT-23-5
G5117T1U
G5119P8U
G5117T1Uf
G5119P8Uf
5117X
G5119
-40°C ~ +85°C
-40°C ~ +85°C
SOT-23-5
MSOP-8L
Note:T1 : SOT-23-5
U : Tape & Reel
P8 : MSOP-8L
Pin Configuration
SW
1
GND 2
Typical Application Circuit
5 VCC
G5115
4 OVP
FB 3
SOT-23-5
SW 1
GND 2
VOUT
5 VCC
VIN
4.7µF/ 6.3V
G5117
PWM Dimming
Waveform
SOT-23-5
VCC 1
SW
C1
C2
1µF/ 25V
4 LEDs
OVP
G5119
4 SHDN
FB 3
D1
L1
VIN
2.7V to 4.2V
SHDN
GND
FB
RS
8 SW
7 AGND
PGND 2
G5119
N.C. 3
6 FB
OVP 4
5 SHDN
MSOP-8
TEL: 886-3-5788833
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Ver: 1.1
Sep 20, 2004
1
G5115/G5117/G5119
Global Mixed-mode Technology Inc.
Absolute Maximum Ratings
SW, OVP to GND……..………..………….-0.3V to +18V
VCC, SHDN to GND..........................…...-0.3V to +7V
FB to GND..........................................……-0.3V to VCC
Operating Temperature…….……………..-40°C to 85°C
Junction Temperature ..........................................125°C
Storage Temperature………...............…-65°C to 150°C
Reflow Temperature (soldering, 10sec).…..……..260°C
Stress beyond those listed under “Absolute Maximum Rating” may cause permanent damage to the device.
Electrical Characteristics
(VCC=V SHDN =3.6V, TA=25°C, unless specified)
PARAMETER
CONDITION
MIN
Input Voltage Range
TYP
MAX
UNIT
V
1.7
---
6.5
G5115/G5119, Trigger
15
16
17
V
G5115/G5119, Release
---
---
14
V
OV Pin Input Current
G5115/G5119, Vovp = 16V
---
10
15
µA
Quiescent Current
VFB = 0.3V
V SHDN = 0V
---
50
100
µA
OV Protection Threshold
FB Comparator Trip Point
---
2.4
3
µA
242
250
258
mV
ns
Switch Off Time
VFB = 0V
---
400
---
Switch RDS(ON)
ISW = 150mA
---
0.8
1.2
Ω
Switch Leakage Current
Switch Off, VSW = 18V
---
0.1
5
µA
Switch Current Limit
200
250
300
mA
SHDN Pin Voltage High
0.9
---
---
V
SHDN Pin Voltage Low
---
---
0.25
V
Note.1:The G5115/G5117/G5119 are guaranteed to meet performance specifications from 0°C~85°C. Specifications
over the -40°C~85°C operating temperature range are assured by design, characterization and correlation
with statistical process controls.
Block Diagram
L1
D1
VOUT
VIN
C2
C1
VCC
BIAS
SHDN
*
SW
SHUTDOWN
LOGIC
OVP**
CTRL
VOUT
LED
Series
FB
+
PUMP CONTROL
OC
DRIVER
COMP
ERROR
COMP
en_sw
+
R2
0.25V
TOFF PULSE
CONTROL
VREF
GND
* SHDN pin only availiable for G5117/G5119
** OVP pin only availiable for G5115/G5119
TEL: 886-3-5788833
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Ver: 1.1
Sep 20, 2004
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G5115/G5117/G5119
Global Mixed-mode Technology Inc.
Typical Performance Characteristics
(VCC = +3.6V, V SHDN = +3.6V, L=10µH, TA=25°C, unless otherwise noted)
Efficiency vs. Input Current
Efficiency vs. Output Current
90
90
VIN=4.2V
85
Efficiency (%)
80
Efficiency (%)
IO=20mA
85
VIN-3.6V
VIN=2.7V
75
70
65
80
75
70
65
4LEDs, CO=1µF
60
4LEDs, CO=1µF
60
0
5
10
15
Load Current (mA)
20
25
1.5
2.5
3 3.5 4 4.5
Input Voltage (V)
5
5.5
6
SW RDS_on vs. Temperature
1.5
1.5
1.25
1.25
SW RDS_on (Ω)
SW RDS_on (Ω)
SW RDS_on vs. Input Voltage
2
1
0.75
0.5
1
0.75
0.5
0.25
0.25
0
0
1.5
2
2.5
3 3.5 4 4.5 5
Input Voltage (V)
5.5
6
-40
6.5
Current Limit vs. Input Voltage
-20
0
20
40
60
Temperature (°C)
80
100
Current Limit vs. Temperature
400
300
Current Limit (mA)
Current Limit (mA)
250
200
150
100
300
200
100
50
0
0
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
-40
-20
0
20
40
60
80
100
Temperature (°C)
Input Voltage (V)
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Ver: 1.1
Sep 20, 2004
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G5115/G5117/G5119
Global Mixed-mode Technology Inc.
Typical Performance Characteristics (Continued)
OVP Trigger Threshold vs. Input Voltage
OVP Trigger Threshold vs. Temperature
17
20
OVP Trigger Threshold (V)
OVP Trigger Threshold (V)
19
16
15
14
18
17
16
15
14
13
12
11
13
10
2
2.5 3 3.5 4 4.5 5
Input Voltage (V)
5.5
6
-40
6.5
-20
0
20
40
60
Temperature (°C)
80
100
OVP Release Threshold vs. Input Voltage
OVP Release Threshold vs. Temperature
14
20
19
13.5
OVP Release Threshold (V)
OVP Release Threshold (V)
1.5
13
12.5
12
11.5
18
17
16
15
14
13
12
11
11
10
1.5
2
2.5 3 3.5 4 4.5 5
Input Voltage (V)
5.5
6
6.5
-40
0
20
40
60
Temperature (°C)
80
100
LED Current vs. Duty Cycle
LED Current vs. Input Voltage
35
25
4LEDs
30
4LEDs
CO=0.1µF
20
25
20
LED Current (mA)
LED Current (mA)
-20
CO=1µF
15
10
CO=0.1µF
15
CO=1µF
10
5
5
0
0
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
0
6.5
Input Voltage (V)
10 20 30 40 50 60 70 80 90 100
Duty Cycle (%)
TEL: 886-3-5788833
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Ver: 1.1
Sep 20, 2004
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Global Mixed-mode Technology Inc.
G5115/G5117/G5119
Typical Performance Characteristics (Continued)
PWM Dimming
OVP Waveform
G5119 Inrush Current Waveform
TEL: 886-3-5788833
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Ver: 1.1
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Global Mixed-mode Technology Inc.
G5115/G5117/G5119
Pin Description
G5115
PIN
G5117
G5119
SOT-23-5
SOT-23-5
MSOP-8
1
1
8
SW
2
2
2
3
3
6
PGND
AGND
FB
4
5
SHDN
4
OVP
1
VCC
4
5
5
7
NAME
FUNCTION
Switch Pin. The drain of the internal NMOS power switch. Connect
this pin to inductor.
Power Ground Pin.
Analog Ground Pin.
Feedback Pin.
Active Low Shutdown Pin. Tie this pin to logical high to enable
the device or tied it to logical low to turn this device off. Internal
1.5MΩ pulled high.
Over Voltage Protection Sense Pin.
Input Supply Pin. Bypass this pin with a capacitor as close to the
device as possible.
Function Description
Applications Information
Operation
The G5115/G5117/G5119 are boost converters with
NMOS switch embedded. They operate in a PFM
scheme with constant peak current control. The operation frequency is up to 1MHz and is determined by the
current limit, inductor value, input voltage and minimum
off time. The boost cycle is started when FB pin voltage
drop below 0.25V as the NMOS switch turns on. During
the switch on period, the inductor current ramps up until
250mA current limit is reached. Then turns the switch
off, while the inductor current flows through external
schottky diode, and ramps down to zero. During the
switch off period, the inductor current provides for load
current and also charges output capacitor. It makes the
LED current higher and results in larger voltage drop on
sense resistor Rs. The cycle stop when FB pin voltage
is above 0.25V.
Inductor Selection
The PFM peak current control scheme of the
G5115/G5117/G5119 is inherently stable. The inductor
value does not affect the stability of the regulator. The
selected inductor must have a saturation current that
meets the maximum peak current of the converter. Another important inductor parameter is the DC resistance.
The lower DC resistance has the higher the efficiency
of the converter.
The current limit function acts as an inherent soft start
by controlling the inrush current.
Output Capacitor Selection
For better output voltage filtering, a low ESR output
capacitor is recommended. Ceramic capacitors have a
low ESR value, but depending on the application, tantalum capacitors can be used. The selection of the
output capacitor value directly influences the output
voltage ripple of the converter which also influences
line regulation. The larger output voltage ripple, the
larger line regulation, which means that the LED current changes if the input voltage changes. If a certain
change in LED current gives a noticeable change in
LED brightness, depends on the LED manufacturer and
on the application. Applications requiring good line
regulation ±1%/V (TYP) must use output capacitor values ±1µF.
Table 1. Recommended Inductors
PART
LQH32CN100K1
VALUE(µH) MAX DCR (Ω) VENDOR
10
0.39
MURATA
1
PWM Dimming
To control the brightness of the LEDs, use a low frequency PWM waveform to turn G5117/G5119 on for
duty 0%~100%. How bright the LEDs at 100% duty are
determined by sense resistor Rs.
Overvoltage Protection (OVP)
OVP is designed to prevent the damage of internal
NMOS switch in case the increased impedance of the
LED load (include the LED opened). Once the device
detects over voltage at the output, the internal NMOS
switch is kept off until the output voltage drops below
14V.
972AS-100M
10
0.48
TOKO
960AW-100M
10
0.18
TOKO
TEL: 886-3-5788833
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Ver: 1.1
Sep 20, 2004
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Global Mixed-mode Technology Inc.
Table 2. Recommended Output Capacitors
VOLTAGE
RATING (V)
PART
VALUE (µF)
TMK107BJ104MA
0.1
25
Tayo Yuden
TMK316BJ105KL
1
25
Tayo Yuden
TMK325BJ475MN
4.7
25
Tayo Yuden
Setting The LED Current
The Converter regulates the LED current by regulating
the voltage across the current sense resistor (RS). The
voltage across the sense resistor is regulated to the
internal reference voltage of V(FB)=250mV. The LED
Current can be calculated:
VENDOR
ILED =
Input Capacitor Selection
For good input voltage filtering the capacitor value can
be increased. Low ESR ceramic capacitors are recommended. A 4.7µF ceramic input capacitor is sufficient for most applications.
VALUE (µF)
VOLTATE
RATING (V)
VENDOR
LMK212BJ105MG
1
10V
Tayo Yuden
JMK212BJ475MG
4.7
6.3V
Tayo Yuden
JMK212BJ106MG
10
6.3V
Tayo Yuden
Table 4. Recommended Diodes
REVERSE
VOLTAGE (V)
VENDOR
MBR0520
20
On Semiconductor
=
0.25V
RS
Layout considerations
In all switching power supplies the layout is an important step in the design, especially at high peak currents
and switching frequencies. If the layout is not carefully
done, the regulator might show noise problems and
duty cycle jitter. The input capacitor should be placed
as close as possible to the input pin for good input
voltage filtering. The inductor and diode must be placed
as close as possible to the switch pin to minimize noise
coupling into other circuits. Since the feedback pin and
network is a high impedance circuit, the feedback network should be routed away from the inductor.
Diode Selection
To achieve high efficiency a Schottky diode must be
used. The current rating of the diode must meet the
peak current rating of the converter. Schottky diodes,
with their low forward voltage drop and fast switching
speed, are best match for the G5115/G5117/G5119.
PART
VFB
RS
The current programming method is used when the
brightness of the LEDs is fixed or control by a PWM
signal applied to the SHDN pin. When using a PWM
signal on the SHDN pin, the LED brightness is only
dependent on the PWM duty cycle, independent of the
PWM frequency or amplitude, which simplifies the systems.
Table 3. Recommended Input Capacitors
PART
G5115/G5117/G5119
TEL: 886-3-5788833
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Ver: 1.1
Sep 20, 2004
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G5115/G5117/G5119
Global Mixed-mode Technology Inc.
Package Information
C
D
L
H
E
θ1
e1
e
A
A2
A1
b
SOT-23-5 Package
Note:
1. Package body sizes exclude mold flash protrusions or gate burrs
2. Tolerance ±0.1000 mm (4mil) unless otherwise specified
3. Coplanarity: 0.1000mm
4. Dimension L is measured in gage plane
SYMBOL
MIN
DIMENSIONS IN MILLIMETER
NOM
MAX
A
A1
1.00
0.00
1.10
-----
1.30
0.10
A2
b
0.70
0.35
0.80
0.40
0.90
0.50
C
D
0.10
2.70
0.15
2.90
0.25
3.10
E
e
1.40
-----
1.60
1.90(TYP)
1.80
-----
e1
H
L
θ1
----2.60
0.37
0.95
2.80
------
----3.00
-----
1º
5º
9º
TEL: 886-3-5788833
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Ver: 1.1
Sep 20, 2004
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Global Mixed-mode Technology Inc.
G5115/G5117/G5119
C
E1
E
L
D
θ
12° (4X)
A2
y
e
A
A1
b
MSOP-8 Package
Note:
1. Package body sizes exclude mold flash and gate burrs
2. Dimension L is measured in gage plane
3. Tolerance 0.10mm unless otherwise specified
4. Controlling dimension is millimeter converted inch dimensions are not necessarily exact.
5. Followed from JEDEC MO-137
SYMBOL
A
A1
A2
b
C
D
E
E1
e
L
y
θ
MIN
DIMENSION IN MM
NOM
MAX
MIN
DIMENSION IN INCH
NOM
MAX
0.81
0.00
0.76
0.28
0.13
2.90
4.80
2.90
----0.40
----0º
1.02
----0.86
0.30
0.15
3.00
4.90
3.00
0.65
0.53
---------
1.22
0.20
0.97
0.38
0.23
3.10
5.00
3.10
----0.66
0.10
6º
0.032
0.000
0.030
0.011
0.005
0.114
0.189
0.114
----0.016
----0º
0.040
----0.034
0.012
0.006
0.118
0.193
0.118
0.026
0.021
---------
0.048
0.008
0.038
0.015
0.009
0.122
0.197
0.122
----0.026
0.004
6º
Taping Specification
Feed Direction
SOT-23-5 Package Orientation
Feed Direction
Typical MSOP Package Orientation
PACKAGE
Q’TY/REEL
SOT-23-5
3,000 ea
MSOP-8
2,500 ea
GMT Inc. does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and GMT Inc. reserves the right at any time without notice to change said circuitry and specifications.
TEL: 886-3-5788833
http://www.gmt.com.tw
Ver: 1.1
Sep 20, 2004
9