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PT6920 Series
Standard Application
25 Watt 5V Input Dual Output
Integrated Switching Regulator
Ordering Information
PT6921
J
J = +3.3 Volts
+2.5/+1.8 Volts
PT6922
J
J = +3.3 Volts
+1.5 Volts
C1 = Req’d 560F electrolytic (1)
C2 = Req’d 330F electrolytic (1)
C3 = Optional 100F electrolytic
Dual Outputs:
+3.3V/6A
+2.5V/2.2A or +1.8V/1.5A
Adjustable Output Voltage
Remote Sense (both outputs)
Standby Function
Over-Temperature Protection
Soft-Start
Internal Sequencing
23-pin SIPPackage
Pin Function
1V1 Remote Sense
2
Do Not Connect
3
STBY
4Vin
5Vin
6Vin
7
GND
8
GND
9
GND
10
GND
11
GND
12
V1out
Pin
Function
13
V1out
14
V1out
15
V1out
16
V1 Adjust
17
Do Not Connect
18
V2out
19
V2out
20
V2out
21
V2out
22
V2 Remote Sense
23
V2 Adjust*
Pin-Out Information
The PT6920 is a series of 25W
dual output ISRs that were purposely
designed to power the latest genera-
tion DSP chips. Both output voltages
are independently adjustable, allowing
either output voltages to be changed
to accomodate a DSP upgrade. The
internal power sequencing of both
outputs meet the requirements of TI’s
‘C6000 series DSPs.
(For dimensions and PC board layout,
see Package Styles 1100 and 1110.)
PT6920
C2
+
GND
V1
OUT
V
IN
GND
4,5,6
7-11
12-15
18-21
16
C1
22
C3
+
23
1
V2
OUT
R1
R2
R3
R4
V2 Sense
V1 Sense
3
STBY
PT Series Suffix (PT1234X)
Case/Pin
Configuration
Vertical Through-Hole
N
Horizontal Through-Hole A
Horizontal Surface Mount
C
Note:
for PT6921 only:
with pin 23 open, V2out=2.5V
with pin 23 shorted to pin 22, V2out=1.8V
Patent Pending*
SLTS042A
(Revised 6/30/2000)
Specifications
Characteristics
PT6920 SERIES
(T
a= 25°C unless noted)
Symbols
Conditions
Min
Typ
Max
Units
Output Current
Io
Ta = +60°C, 200 LFM, pkg N
V1 = 3.3V
0.1 (2)
—
5.5 (3)
V2 = 2.5V
0
—
2.2 (3)
A
V2 = 1.8V
0
—
1.75(3)
V2 = 1.2V
0
—
1.2 (3)
Ta = +25°C, natural convection V1 = 3.3V
0.1
—
6.0
V2 = 2.5V
0
—
2.2
A
V2 = 1.8V
0
—
1.75
V2 = 1.2V
0
—
1.2
Input Voltage Range
Vin
0.1A
≤ Io ≤ Imax
4.5
—
5.5
V
Output Voltage Tolerance
Vo
Vin = +5V, Io = Imax, both outputs
Vo-0.1
—
Vo+0.1
V
0°C
≤ Ta ≤ +65°C
Line Regulation
Regline
4.5V
≤ Vin ≤ 5.5V, Io = Imax
V1 = 3.3V
—
±7
±17
mV
V2 = 2.5V
—
±7
±13
Load Regulation
Regload
Vin = +5V, 0.1 ≤ Io ≤ Imax
V1 = 3.3V
—
±17
±33
mV
V2 = 2.5V
—
±4
±10
Vo Ripple/Noise
Vn
Vin = +5V, Io = Imax
V1 = 3.3V
—
50
—
mV
V2 = 2.5V
—
25
—
Transient Response
ttr
Io step between 0.5xImax and Imax
—
25
—
Sec
with C2 = 330F
Vos
Vo over/undershoot
V1 = 3.3V
—
60
—
mV
V2 = 2.5V
—
60
—
Efficiency
η
Vin = +5V, Io = 4A total
—
75
—
%
Switching Frequency
o
4.5V
≤ Vin ≤ 5.5V
475
600
725
kHz
0.1A
≤ Io ≤ Imax
Absolute Maximum
Ta
Over Vin Range
–40 (4)
—
+85 (5)
°C
Operating Temperature Range
Storage Temperature
Ts
—
-40
—
+125
°C
Weight
—
Vertical/Horizontal
—
29
—
grams
Notes: (1) The PT6920 series requires a 560F electrolytic capacitor on the input and a 330F electrolytic capacitor on the output for proper operation in all applications.
(2) Iomin current of 0.1A can be divided btween both outputs; V1, or V2. The ISR will operate down to no-load with reduced specifications.
(3) Iomax listed for each output assumes the maximum current drawn simultaneously on both outputs. Consult the factory for the absolute maximum.
(4) For operating temperatures below 0°C, use tantalum type capacitors on both the input and output.
(5) See Safe Operating Area curves for appropriate derating.