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Электронный компонент: G5104

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Ver: 1.2
Mar 01, 2005
TEL: 886-3-5788833
http://www.gmt.com.tw
1
G5104
Global Mixed-mode Technology Inc.
300mA Alkaline Boost DC/DC Converters in SOT-23-5
Features
Configurable Output Voltage Up to 5.5V
40A Quiescent Current
<1A Shutdown Current
<1A Shutdown Pin Current
Supply Range from 1.7V to 5.5V
Low V
DS(on)
: 120mV (I
SW
=400mA)
Tiny SOT-23-5 Package
Applications
Personal Digital Assistants (PDAs)
Handheld Computers
Digital Still Cameras
Cellular Phones
WebPad
Local 3V to 5V Conversion
General Description
The G5104 boost converter is designed for 3.3V/5V
powered system.
Due to a typical 40A quiescent current and 1.7V~
5.5V supply voltage range, it is suitable for battery
powered portable applications. Such as PDAs and
Handheld Computers. When the IC sets to shutdown
mode, it only consumes less than 1A.
Furthermore, the 500mA current limit, 450ns fixed
minimum off-time and tiny SOT23-5 package facili-
tates the use of smaller inductor and other sur-
face-mount components to minimize the PCB size in
those space-conscious applications.
To control the IC, no other external current is needed
for the shutdown pin. It typically consumes less than
1A of full supply range.
Ordering Information
ORDER
NUMBER
ORDER NUMBER
(Pb free)
MARKING TEMP.
RANGE PACKAGE
G5104T11U
G5104T1Uf
5104X
-40C ~ +85C
SOT-23-5
Note:T1: SOT-23-5
U: Tape & Reel


Pin Configuration
Typical Application Circuit
G963
VCC
SHDN
SOT-23-5
G5104
5
4
1
SW
2
3
GND
FB
VCC
SW
SHDN
FB
GND
G5104
47F
47F
4.7H
316k
V
IN
3V
1M
5V
300mA
10pF
(option)
G963
VCC
SHDN
SOT-23-5
G5104
5
4
1
SW
2
3
GND
FB
VCC
SW
SHDN
FB
GND
G5104
47F
47F
4.7H
316k
V
IN
3V
1M
5V
300mA
10pF
(option)
Ver: 1.2
Mar 01, 2005
TEL: 886-3-5788833
http://www.gmt.com.tw
2
G5104
Global Mixed-mode Technology Inc.
Absolute Maximum Ratings
SW to GND.........................................-0.3V to +7V
FB to GND............... ............................-0.3V to V
CC
VCC,
SHDN
to
GND...................................-0.3V to +7V
Operating Temperature Range (Note 1) -40C to +85C

Junction Temperature ......................................+125C
Storage Temperature........................-65C to +150C
Reflow Temperature (Soldering, 10 sec)..........+260C
Stress beyond those listed under "Absolute Maximum Rating" may cause permanent damage to the device.
Electrical Characteristics
(V
CC
= 3.6V,
V
SHDN
= 3.6V, T
A
=
25C
)
PARAMETER CONDITIONS
MIN
TYP
MAX
UNITS
Input Voltage Range
1.7
---
5.5
V
Not Switching
---
40
80
A
Quiescent Current
V
SHDN
= 0V
--- 0.1 1 A
FB Comparator Trip Point
1.18
1.2
1.22
V
Output Voltage Line Regulation
2.5V<V
IN
<5.5V
--- -0.05 --- %/V
FB Pin Bias Current (Note 2)
V
FB
= 1.2V
---
---
1
A
Switch Off Time
---
450
---
ns
Switch V
DS(ON)
I
SW
= 0.4A
---
120
160
mV
Switch Current Limit
400
500
600
mA
SHDN
Pin Current
---
0.1
1
A
SHDN
Input Voltage High
0.9
---
---
V
SHDN
Input Voltage Low
---
---
0.25
V
Switch Leakage Current
Switch Off, V
SW
= 7V
---
0.01
5
A
Note 1: The G5104 are guaranteed to meet performance specifications from 0C to 85C. Specifications over the
-40C to 85C operating temperature range are assured by design, characterization and correlation with
statistical process controls.
Note 2: Bias current flows into the FB pin.
Block Diagram
+
+
VREF
BIAS
SHUTDOWN
LOGIC
C2
SW
L1
SHDN
VCC
C1
R1
R2
V
OUT
FB
ERROR
COMP
1.2V
en_sw
GND
PUMP CONTROL
OC
COMP
DRIVER
T
OFF
PULSE
CONTROL
V
OUT
V
IN
C3
(option)
+
+
VREF
BIAS
SHUTDOWN
LOGIC
C2
SW
L1
SHDN
VCC
C1
R1
R2
V
OUT
FB
ERROR
COMP
1.2V
en_sw
GND
PUMP CONTROL
OC
COMP
DRIVER
T
OFF
PULSE
CONTROL
V
OUT
V
IN
C3
(option)
Ver: 1.2
Mar 01, 2005
TEL: 886-3-5788833
http://www.gmt.com.tw
3
G5104
Global Mixed-mode Technology Inc.
Typical Performance Characteristics
(V
CC
=+3V, V
SHDN
=+3V, L=4.7H, T
A
=25C, unless otherwise noted.)

0
0.3
0.6
0.9
1.2
1.5
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
Input Voltage (V)
Feedback Voltage (V)
0
0.3
0.6
0.9
1.2
1.5
-40
-20
0
20
40
60
80
100
Temperature (C)
Feedback Voltage (V)
0
100
200
300
400
500
600
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
Input Voltage (V)
RDS_on (m
)
0
100
200
300
400
-40
-20
0
20
40
60
80
100
Temperature (C)
RDS_on (m
)
0
100
200
300
400
500
600
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
Input Voltage (V)
Current Limit (mA)
0
100
200
300
400
500
600
700
800
-40
-20
0
20
40
60
80
100
Temperature (C)
Current Limit (mA)
Feedback Voltage vs. Input Voltage
Feedback Voltage vs. Temperature
RDS_on vs. Input Voltage
RDS_on vs. Temperature
Current Limit vs. Input Voltage
Current Limit vs. Temperature
Ver: 1.2
Mar 01, 2005
TEL: 886-3-5788833
http://www.gmt.com.tw
4
G5104
Global Mixed-mode Technology Inc.
Typical Performance Characteristics
(continued)
60
65
70
75
80
85
90
1.5
2
2.5
3
3.5
4
4.5
Input Voltage (V)
Efficiency (%)
V
O
=5V, I
O
=100mA
60
65
70
75
80
85
90
0.1
1
10
100
1000
Output Current (mA)
Efficiency (%)
V
IN
=4.2V
V
IN
=3.6V
V
IN
=1.7V
V
IN
=2.4V
V
IN
=3.0V
Efficiency vs. Input Voltage
Efficiency vs. Output Current
Line Transient
Load Transient
Ver: 1.2
Mar 01, 2005
TEL: 886-3-5788833
http://www.gmt.com.tw
5
G5104
Global Mixed-mode Technology Inc.
Pin Description
PIN NAME
FUNCTION
1
SW
Switch Pin. The drain of the internal NMOS power switch. Connect this pin to inductor.
2 GND
Ground.
3 FB
Feedback Pin. Set the output voltage by selecting values for R1 and R2 (see Block Diagram):
R1 = R2
2
.
1
V
OUT
-1
4
SHDN
Active-Low Shutdown Pin. Tie this pin to logic-high to enable the device or tied it to logic-low to turn this
device off.
5
VCC
Input Supply Pin. Bypass this pin with a capacitor as close to the device as possible.

Function Description
The G5104 is a boost converter with a NMOS
switch embedded (refer to Block Diagram). The
boost cycle is getting started when FB pin voltage
drop below 1.2V as the NMOS switch turns on.
During the switch on period, the inductor current
ramps up until 500mA 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 cur-
rent charges output capacitor and the output volt-
age is boosted up. This pumping mechanism con-
tinues cycle by cycle until the FB pin voltage ex-
ceed 1.2V and entering the none switching mode.
Applications Information
Choosing an Inductor
There are several recommended inductors that work
well with the G5104 in Table 1. Use the equations and
recommendations in the next few sections to find the
proper inductance value for your design.
Table 1. Recommended Inductors
PART VALUE
(H) MAX DCR () VENDOR
LQH3C4R7
LQH3C100
LQH3C220
4.7
10
22
0.26
0.30
0.92
Murata
www.murata.com
972AS-4R7M
972AS-100M
A914BYW-4R7
M
A914BYW-100M
4.7
10
4.7
10
0.22
0.48
0.072
0.125
TOKO
www.toko.co.jp

Current Limit Overshoot
The G5104 use a constant off-time control scheme,
the power switch is turned off after the 500mA current
limit is reached. When the current limit is reached and
when the switch actually turns off, there is a 100ns
delay time. During this time, the inductor current ex-
ceeds the current limit by a small amount. The formula
below can calculate the peak inductor current.
I
PEAK
= I
LIM
+
L
V
V
SAT
)
MAX
(
IN
-
x 100ns

Where V
SAT
= 0.2V (switch saturation voltage). When
the systems with high input voltages and uses smaller
inductance value, the current overshoot will be most
apparent. This overshoot can be useful as it helps in-
crease the amount of available output current. To use
small inductance value for systems design, the current
limit overshoot can be quite high. Even if it is internally
current limited to 500mA, the power switch of the
G5104 can operate larger currents without any prob-
lem, but the total efficiency will suffer. The I
PEAK
is keep
below 700mA for the G5104 will be obtained best per-
formance.
Capacitor Selection
Low ESR (Equivalent Series Resistance) capacitors
should be used at the output to minimize the output
ripple voltage and the peak-to-peak transient voltage.
Multilayer ceramic capacitors (MLCC) are the best
choice, as they have a very low ESR and are available
in very small packages. Their small size makes them a
good match with the G5104's SOT-23 package. If solid
tantalum capacitors (like the AVX TPS, Sprague 593D
families) or OS-CON capacitors are used, they will
occupy more volume than a ceramic ones and the
higher ESR increases the output ripple voltage. Notice
that use a capacitor with a sufficient voltage rating.
A low ESR surface-mount ceramic capacitors also
make a good selection for the input bypass capacitor,
which should be placed as close as possible to the
G5104. A 47F input capacitor is sufficient for most
applications.