1.General Description
MDT7730 is a step-up DC/DC converter .
It has low start-up voltage and a high output
voltage accuracy with low ripple.
2. Features
High output voltage accuracy+/- 2.5%
Low start-up voltage: 0.75V (Typ.)
High efficiency: 85% (Typ.)
3. Applications
Cellular phones, pagers, mcu
Power failure detection
Portable / Battery-Powered Equipment
Palmtops
RF Keyboard / Mouse
4. Pin Function Description
MDT7730
1
2
3
VSS VOUT LX
Pin Name
I/O
Function
Ground
LX
Open
Drain
Switching pin
VOUT
Input
Output voltage
monitor, IC internal
power supply
ORDERING INFORMATION
Device
Package
MDT7730ST
SOT89
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2005/10/18
5. Electrical Characteristics
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
Output Voltage
----------------
2.925
3
3.075
V
Output Ripple
----------------
2.5
3
%
Vin
----------------
6
V
Iout=1mA
0.75
0.8
V
Vstart
Iout=30mA
1.1
1.2
V
Iout=1mA
0.7
V
Vhold
Iout=30mA
1
V
Iin
Without loading
20
25
uA
Supply Current IDD1 VIN=VOUT
0.95
Measured at VOUT pin
without external component
45
52
uA
Supply Current IDD2 VIN=VOUT+0.5V
Measured at VOUT pin
without external component
8
12
uA
Shutdown Current
VCE=0 , VIN=VOUT
0.95
0.5
uA
LX Leakage Current VIN=6V
1
uA
Maximum Oscillator
Frequency
VIN=VOUT0.95
Measured at ETR pin
200
230
kHz
Oscillator Duty Cycle VIN=VOUT
_
0.95
Measured at ETR pin
70
75
80
%
Efficiency
L , SD , CL etc. connected
85
%
+3.0V Output Type
VIN=VOUT
0.6 ; IOUT=30mA ; Ta=25
(Unless otherwise specified)
Note:
" Supply current 1 " is the supply current while the oscillator is continuously oscillating. In
actual operation the oscillator periodically operates. The current actually provided by an
external VIN source from VOUT pin.
" Supply current 2 " is the supply current while the oscillator stop oscillating. In actual
operation the oscillator periodically operates. The current actually provided by an external
VIN source from VOUT pin
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6.Application Circuit
EXTERNAL COMPONENT : Cin=100uF ; CL=100uF ; Cb=0.1uF
L=100uH
7.TYPICAL PERFOMACE OF EFFICIENCY
EFFICIENCY
0
10
20
30
40
50
60
70
80
90
100
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
mA
%
2.0V
1.8V
1.5V
1.2V
0.9V
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