TI PT7708

PT7709—5V
20 Amp Programmable
Next Generation “Big Hammer”
SLTS084
(Revised 6/30/2000)
Description
The PT7709 is a next generation
“Big Hammer”, high-performance
Integrated Switching Regulator (ISR),
which is made available in Power
Trends’ aluminum 27-pin SIP package. The PT7709 improves on the
popular PT7705 with 20A of output
current and short circuit protection.
The PT7709 is suitable for existing 5V system designs that require
power for the latest high-speed, low-
voltage µPs, and bus drivers.
The PT7709 output is programmable from 1.3V to 3.5V with a 5-bit
input, which is compatible with the
Intel Pentium Processor. A differential
remote sense is also provided to compensate for voltage drop between the
ISR and load.
Only 330µF of output capacitance
are required for proper operation.
Pin-Out Information
Standard Application
PROGRAMMING PINS
VID0
VID1
VID2
VID3
VID4
REMOTE SENSE (+)
6
4
3
2
1
V IN
7-11
PT7709
Vin
1 H
+
SYNC OUT
STBY
Synch
Out
5
27
C IN
26
SNS(+)
VID4 - VID0
L1
GND
13-19
Vo
VOUT
20-25
SNS(-)
+
12
LOAD
COUT
GND
GND
Pin Function
Pin Function
Pin Function
1
VID0
10
Vin
19
GND
2
3
VID1
VID2
11
12
Vin
20
21
Vout
Vout
4
5
VID3
STBY* - Stand-by
13
14
GND
GND
22
23
Vout
Vout
6
7
VID4
Vin
15
16
GND
GND
24
25
Vout
Vout
8
9
Vin
Vin
17
18
GND
GND
26
27
Sync Out
REMOTE SENSE ( )
STBY*
Cin = Required 1500µF electrolytic
Cout= Required 330µF electrolytic
L1 = Optional 1µH input choke
Remote Sense Gnd
(4)
Remote Sense Vout
For STBY* pin:
open = output enabled
ground = output disabled.
Specifications
PT7709 SERIES
Characteristics
(Ta = 25°C unless noted)
Symbols
Conditions
Min
Typ
Max
Units
Output Current
Io
Ta = +60°C, 200 LFM, pkg N
Ta = +25°C, natural convection
0.1 (1)
0.1 (1)
—
—
20
20
A
A
Input Voltage Range
Vin
0.1A ≤ Io ≤ 20A
4.5
—
5.5
V
Output Voltage Tolerance
∆Vo
Vin = +5V, Io = 20A
0°C ≤ Ta ≤ +65°C
Vo-0.03
—
Vo+0.03
V
Line Regulation
Regline
4.5V ≤ Vin ≤ 5.5V, Io = 20A
—
±10
—
mV
Load Regulation
Regload
Vin = +5V, 0.1 ≤ I o ≤ 20A
—
±10
—
mV
Vo Ripple/Noise
Vn
Vin = +5V, Io = 20A
—
50
—
mV
Transient Response
with Cout = 330µF
ttr
Vos
Io step between 10A and 20A
Vo over/undershoot
—
—
50
100
—
—
µSec
mV
Efficiency
η
Vin = +5V, Io = 10A
Vo = 3.3V
Vo = 2.5V
Vo = 1.8V
—
—
—
92
90
87
—
—
—
%
%
%
Vin = +5V, Io = 20A
Vo = 3.3V
Vo = 2.5V
Vo = 1.8V
—
—
—
90
87
82
—
—
—
%
%
%
350
400
—
+85
Switching Frequency
ƒo
4.5V ≤ Vin ≤ 5.5V
0.1A ≤ Io ≤ 20A
300
Absolute Maximum
Operating Temperature Range
Ta
Over Vin
–40
Storage Temperature
Ts
and Io Ranges
(2)
kHz
(3)
°C
—
–40
—
+125
°C
Mechanical Shock
Per Mil-STD-883D, Method 2002.3
1 msec, Half Sine, mounted to a fixture
—
500
—
G’s
Mechanical Vibration
Per Mil-STD-883D, Method 2007.2,
20-2000 Hz, Soldered in a PC board
—
10
—
G’s
Vertical/Horizontal
—
31/41
—
grams
Weight
Notes: (1)
(2)
(3)
(4)
—
ISR-will operate down to no load with reduced specifications.
For operation below 0°C, Cin and Cout must have stable characteristics. Use either low ESR tantalum or Oscon® capacitors.
See Safe Operating Area curves or contact the factory for the appropriate derating.
If the Remote Sense Ground is not used, pin 12 must be connected to pin 13 for optimum output voltage accuracy.
External Capacitors: The PT7709 requires a minimum output capacitance of 330µF for proper operation. The PT7709 also requires an input capacitance of 1500µF,
which must be rated for a minimum of 1.4Arms of ripple current. For transient or dynamic load applications, additional capacitance may be required. For more
information refer to the application note regarding capacitor selection for this product.
Input Filter: An input filter inductor is optional for most applications. The inductor must be sized to handle 20ADC with a typical value of 1µH.
For technical support and more information, see inside back cover or visit www.ti.com/powertrends
PT7709—5V
20 Amp Programmable
Next Generation “Big Hammer”
Features
Programming Information
• Single-Device: +5V input
• 5-bit Programmable:
1.3V to 3.5V@20A
• High Efficiency
• Differential Remote Sense
• Short-Circuit Protection
• Parallelable with PT7743
20A “Current Booster”
VID3 VID2 VID1 VID0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
Ordering Information
PT7709❏
❏ = 1.3 to 3.5 Volts
VID4=1 VID4=0
Vout
Vout
2.0V
2.1V
2.2V
2.3V
2.4V
2.5V
2.6V
2.7V
2.8V
2.9V
3.0V
3.1V
3.2V
3.3V
3.4V
3.5V
(For dimensions and PC board layout,
see Package Styles 800 and 810.)
1.30V
1.35V
1.40V
1.45V
1.50V
1.55V
1.60V
1.65V
1.70V
1.75V
1.80V
1.85V
1.90V
1.95V
2.00V
2.05V
PT Series Suffix (PT1234X)
Case/Pin
Configuration
Vertical Through-Hole
N
Horizontal Through-Hole A
Horizontal Surface Mount C
Logic 0 = Pin 12 potential (remote sense gnd)
Logic 1 = Open circuit (no pull-up resistors)
VID3 and VID4 may not be changed while the unit is operating.
T Y P I C A L
PT7709 Performance, Vo = 3.3 VDC
C H A R A C T E R I S T I C S
Safe Operating Area Curves
(See Note A)
(See Note B)
VIN =5.0V, Vo =3.3 VDC
Efficiency vs Output Current
100
90.0
Efficiency - %
VOUT
80
3.3V
2.5V
1.8V
70
60
Ambient Temperature ( C)
80.0
90
70.0
Airflow
200LFM
120LFM
60LFM
Nat conv
60.0
50.0
40.0
30.0
50
20.0
0
4
8
12
16
20
0.0
5.0
Iout (A)
10.0
15.0
20.0
Iout (A)
VIN =5.0V, Vo =1.8 VDC
Ripple vs Output Current
50
90.0
Ripple - mV
VOUT
30
3.3V
2.5V
1.8V
20
10
Ambient Temperature ( C)
80.0
40
70.0
Airflow
200LFM
120LFM
60LFM
Nat conv
60.0
50.0
40.0
30.0
0
20.0
0
4
8
12
16
20
0.0
Iout (A)
4.0
8.0
12.0
16.0
20.0
Iout (A)
Power Dissipation vs Output Current
10
8
Pd - Watts
VOUT
6
1.8V
2.5V
3.3V
4
2
0
0
4
8
12
16
20
Iout (A)
Note A: All data in the above graphs has been developed from actual products tested at 25°C. The data is considered typical for the ISR
Note B: SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures.
For technical support and more information, see inside back cover or visit www.ti.com/powertrends
Application Notes
PT7708/PT7709, PT7742/PT7743
Capacitor Recommendations for the PT7708/09
Regulators and PT7742/43 Current Boosters
Input Capacitors
The recommended input capacitance is determined by
1.4 ampere minimum ripple current rating and 1500µF
minimum capacitance. Capacitors listed below must be
rated for a minimum of 2x the input voltage with +5V
operation. Ripple current and ≤100mΩ Equivalent Series
Resistance (ESR) values are the major considerations along
with temperature when selecting the proper capacitor.
Output Capacitors
The minimum required output capacitance is 330µF with
a maximum ESR less than or equal to 100mΩ. Failure to
observe this requirement may lead to regulator instability
or oscillation. Electrolytic capacitors have poor ripple performance at frequencies greater than 400kHz, but excellent
low frequency transient response. Above the ripple frequency ceramic decoupling capacitors are necessary to
improve the transient response and reduce any microprocessor high frequency noise components apparent during
higher current excursions. Preferred low ESR type capacitor part numbers are identified in the Table 1 below.
Tantalum Characteristics
Tantalum capacitors with a minimum 10V rating are
recommended on the output bus, but only the AVX TPS
Series, Sprague 594/595 Series, or Kemet T495/T510 Series.
The AVX TPS Series, Sprague Series or Kemet Series
capacitors are specified over other types due to their
higher surge current, excellent power dissipation and ripple
current ratings. As an example, the TAJ Series by AVX is
not recommended. This series exhibits considerably higher
ESR, reduced power dissipation and lower ripple current
capability. The TAJ Series is a less reliable compared to
the TPS series when determining power dissipation capability.
Capacitor Table
Table 1 identifies the characteristics of capacitors from a
number of vendors with acceptable ESR and ripple current
(rms) ratings. The suggested minimum quantities per regulator for both the input and output buses are identified.
This is not an extensive capacitor list. The table below is a
selection guide for input and output capacitors. Other capacitor
vendors are available with comparable RMS ripple current rating
and ESR (Equivalent Series Resistance at 100kHz). These
critical parameters are necessary to insure both optimum regulator
performance and long capacitor life.
Table 1 Capacitors Characteristic Data
Capac i t or
Ve n d o r /
Ser i es
Capac i t or Char ac t e r i s t i c s
Qu a n t i t y
Working
Voltage
Value(µF)
( ESR) Equi v al e nt
Se r i e s Re s i s t anc e
1 0 5 ° C Ma x i m u m
Ri ppl e
C u r r e n t ( I r ms )
Phy s i c al
S i z e ( mm)
I nput
Bu s
Ou t p u t
Bu s
Panasonic
FC
Surface Mtg
FA
16V
35V
2200
330
0.038Ω
0.065Ω
2000mA
1205mA
18x16.5
12.5x16.5
1
1
1
EEVFC1C222N
EEVFC1V331LQ
10V
16V
680
1800
0.090Ω
0.032Ω
755mA
2000mA
10x12.5
18x15
1
1
1
EEUFA1A681
EEUFA1C182A
United
Chemi -Con
LFVSeries
25V
16V
16V
330
2200
470
0.084Ω
0.038Ω
0.084Ω/2=042Ω
825mA
1630mA
825mA x2
10x16
16x20
10x16
1
1
1
1
LXV25VB331M10X16LL
LXV16VB222M16X20LL
LXV16VB471M10X16LL
Nichicon
PL Series
PM Series
10V
10V
25V
680
1800
330
0.090Ω
0.044Ω
0.095Ω
770mA
1420mA
750mA
10x15
16x15
10x15
1
1
1
1
UPL1A681MHH6
UPL1A182MHH6
UPL1E331MPH6
Oscon SS
SV
10V
10V
330
330
0.025W/4=0.006Ω
0.020/4=0.005Ω
>9800mA
>9800mA
10x10.5
10.3x12.6
4
4
N/R
(Note)
AVX
Tanatalum
TPS- Series
10V
10V
330
330
0.100/5=20Ω
0.060Ω
3500mA
1826mA
7.3Lx
4.3Wx
4.1H
5
5
1
1
TPSV337M010R0100
TPSV337M010R0060
Sprague
Tantalum
595D/594D
10V
330
0.045W/4=0.011Ω
>4500mA
5
1
10V
680
0.090Ω
>1660mA
7.3L x
5.7W x
4.0H
2
1
594D337X0010R2T
Surface Mount
595D687X0010R2T
Kemet
Tantalum
T510/T495
Series
10V
330
0.035Ω
2000mA
10V
220
0.070Ω/2=0.035Ω
>2000mA
Sanyo Poscap
TPB
10V
220
0.040Ω
3000mA
4.3Wx7.3L
x4.0H
7.2L x
4.3W x
3.1H
Note: (N/R) is not recommended for this application, due to extremely low Equivalent Series Resistance (ESR)
For technical support and more information, see inside back cover or visit www.ti.com/powertrends
Vendor Number
10SS330M
10SV330M(Sufvace Mtg
5
1
510X337M010AS
6
2
T495X227M010AS
Surface Mount
6
2
10TPB220M
Surface Mount
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