2.5V to 12V
Output MD1322F
DESCRIPTION
Company Name
28
TAB2
15
Type No.
The MD1322F is a high-efficiency step down DC-DC converter
power integrated circuit with main MOSFET switch and Schottky
Barrier Diode. The MD1322F can deliver 7.5 watts maximum
(5V, 3.0A) with high efficiency over a wide input voltage range.
This device has output voltage digitally selectable from 2.5V to 12V.
With the MD1322F you can construct a complete DC-DC converter
using only a few external components. Featuring an HSOP 28-pin
SHINDENGEN
MD1322F
5030N
1
TAB1
14
–
12.23
+ 0.3
–
8.8
+ 0.1
Lot No.
surface mount package, the MD1322F allows you to incorporate
a very small and thin power supply on your circuit board.
BLOCK DIAGRAM
Vref
26
FEATURES
Vboot
6
Vcc
5
VB
23
VG
22
V
DD
TAB2
s
High efficiency
s
Wide input voltage load range
8VDC to 30VDC
Up to 3ADC
s
Output voltage selectable function
START UP
START=7.2V
STOP=6.7V
BOOT Reference
Vref=6.5V
Driver
Vref=Vout+5.8V
Reference
Vref=5V±5%
TSD
100˚C
150˚C
Main Switch
MOS OFF
driver
2.5V to 12V
s
Internal Switching power device
TAB1
Error amp
-
+
2.45V
PWM comp
+
VOUT
Main MOSFET for switch
SBD for rectification
s
Fixed 250kHz PWM frequency
Without external resistor and capacitor
s
Overcurrent protection
-
Q
3V
1V
OSC
f=250kHz
CLM Vth=
0.1~0.2V
R
S
+
-
28
27
1
2
3
4.24
8-11
amp-
ampOUT
S/S
OCL-
OCL+
GND
P.GND
s
Thermal shutdown function
PIN ASSIGNMENT
Pin#
1
2
3
4
VOUT:TAB1
TAB2:V
DD
S/S: 1
OCL-: 2
OCL+: 3
GND: 4
Vcc: 5
Vboot: 6
N/C: 7
28: amp-
27: ampOUT
26: Vref:
25: VTS
24: GND
23: VB
22: VG
Symbol
S/S
OCL-
OCL+
GND
Vcc
Vboot
N/C
P.GND
N/C
VG
VB
GND
VTS
Vref
AmpOUT
amp-
VOUT
VDD
Function description
Capacitor for softstart
Overcurrent protection (OCL) (-)
Overcurrent protection (OCL) (+)
Signal GND
Input voltage
High side drive supply for main MOS
Non-connection
Power GND
Non-connection
Gate terminal of main MOS
Bootstrap capacitor between VB and VOUT
Signal GND
Output voltage selectable terminal
Internal voltage reference
Error Amp out
Error Amp (-) input
Power stage output
Drain of main MOS Switch
5
6
7
8 ~ 11
12 ~ 21
22
23
24
25
26
27
28
TAB1
TAB2
P.GND: 8
P.GND: 9
P.GND: 10
P.GND: 11
N/C: 12
N/C: 13
N/C: 14
21: N/C
20: N/C
19: N/C
18: N/C
17: N/C
16: N/C
15: N/C
s
Vref
- Temperature compensated internal voltage. You can pull 1mA
maximum for external circuit.
s
OSC
- Uses internal oscillator without external component.
Frequency (Saw tooth wave form) is trimmed to 250kHz on chip.
s
Error Amp
- Error Amp detects output voltage of DC-DC converter
and controls PWM signal. You can adjust the loop gain when you
connect feedback resistor and capacitor between AmpOUT and
Amp (-). It will provide stable phase compensation.
s
Overcurrent protection
- Uses pulse-by-pulse current
protection. Current will be sensed voltage drop of external current
sensing resistor. Threshold of OCL is 0.19V.
1 - 8 0 0 - 6 3 4 - 3 6 5 4
2.5V-12V
Output MD1322F
ABSOLUTE MAXIMUM RATINGS
Parameter
Line voltage
Output MOS input voltage
Output current (AVE)
Output Current (PEAK)
OCL-,OCL+terminal voltage
Storage temperature
Junction temperature
Symbol
V
IN
V
DD
I
OUT
ave
I
OUT
peak
V
OCL
Tstg
Tj
Rating
32
32
3
4
5.5
-40 ~ 150
150
(Ta=25°C)
Units
V
V
A
A
V
°C
°C
Output setting voltage
2.5V ~5.3V
<
= 6V
<
= 8V
<
= 12V
Output current
3A
2.5V
2A
1.5A
RECOMMENDED OPERATION CONDITIONS
Parameter
Input voltage
Output voltage setting range
Operation temperature
Recommendation
8 ~ 30
2.5 ~ 12
-10 ~ 80
Units
V
V
°C
OUTPUT CURRENT DERATING FOR 5.3V OR
HIGHER OUTPUT
ELECTRICAL CHARACTERISTICS
Parameter
High side MOS
D - S voltage
High side MOS
Drain interruption current
High side MOS
Drain-source ON resistance
High side MOS
Source-drain Di forward voltage
Low side SBD
Peak reverse voltage
Low side SBD
Forward voltage
Low side SBD
Reverse current
Start
voltage
Stop
voltage
Stop-start
voltage hysteresis
Current consumption
BOOT terminal voltage
Internal reference voltage
Initial oscillation
frequency
Overcurrent threshold voltage
Softstart
terminal current
Error amplifier reference voltage
Overcurrent protection
operating temperature
Symbol
Conditions
I
D
=1mA, V
GS
=0V
V
DS
=30V, V
GS
=0V
MIN
TYP
MAX
-
10
250
1.5
-
0.55
2
7.9
7.4
-
10
7.6
5.25
287.5
0.218
-5
2.5
-
(Ta=25°C)
Units
Vdss
Idss
Ron
V
SD
V
RM
V
F
I
R
Vcc_start
Vcc_stop
Vcc_hys
Icc
Vboot
Vref
fosc
Vth_OCL
I
S
/
S
Vamp
T_TSD
32
-
-
-
40
-
-
6.5
6.0
-
-
5.4
4.75
212.5
0.162
-20
2.4
-
-
-
140
-
-
-
-
7.2
6.7
0.5
8
6.5
5
250
0.19
-12.5
2.45
150
V
uA
mΩ
V
V
V
mA
V
V
V
mA
V
V
kHz
V
uA
V
°C
I
D
=1.2A, V
GS
=4V
I
S
=1.2A, V
DS
=0V
-
I
F
=1.2A
V
R
=V
RM
-
-
-
Vcc=8V ~ 30V
Vcc=8V ~ 30V
Vcc=8V ~ 30V
Vcc=24V
Vcc=24V
Vcc=24V
Vcc=8V ~30V
-
1 - 8 0 0 - 6 3 4 - 3 6 5 4
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