TI PT7743N

PT7615—5V
20-A Low-Voltage Programmable
Integrated Switching Regulator
SLTS163
(Revised 12/13/2001)
Features
• Single-Device: +5V Input
• 20A Output
• 5-bit Programmable:
1.075V to 1.85V (25mV Steps)
• VRM 9.0 Compatible
• High Efficiency (87%)
• Differential Remote Sense
• Short-Circuit Protection
• Compatible with PT7743
20A “Current Booster”
Description
Ordering Information
Pin-Out Information
The PT7615 power module is a 20-A
fully integrated switching regulator (ISR)
housed in a 27-pin aluminum SIP package.
Operating from a 5V-input bus, the
PT7615 produces a tightly regulated
supply voltage that is programmable over
the range, 1.075V to 1.85V. The output
voltage is selected via a 5-bit code. The
code adjusts the voltage in steps of 25mV
and is VRM 9.0 compatible.
This regulator is most suitable for
applications that employ microprocessor
and DSP products that require core supply
voltages as low as 1.075V.
The PT7615 includes a Shutdown
control, Differential Remote Sense, and
Short-Circuit Protection.
PT7615o = 1.075 to 1.85Volts
PT7743o = 20A Booster
PT Series Suffix (PT1234 x )
Case/Pin
Configuration
Order
Suffix
Package
Code
N
A
C
Vertical
Horizontal
SMD
Pin Function
Pin Function
1
VID0
15
GND
2
VID1
16
GND
3
VID2
4
5
VID3
STBY *
17
18
GND
GND
19
GND
6
VID4
20
7
Vin
Vin
Vin
21
22
Vout
Vout
Vout
24
Vout
Vout
11
Vin
Vin
12
13
Remote Sense (–)
GND
25
26
Vout
Remote Sense (+)
27
Sync Out
14
GND
8
9
(EHD)
(EHA)
(EHC)
10
(Reference the applicable package code drawing for the dimensions and PC board layout)
23
For STBY* pin: open =output enabled
ground =output disabled.
Standard Application
VID0
VID1
VID2
VID3
VID4
PROGRAMMING PINS
REMOTE SENSE(+)
6 4 3 2 1
26
L1
VIN
7-11
1µH
+
C IN
27
5
13-19
VO U T
20-25
PT7615
12
SYNC OUT
L
O
A
D
+
C OUT
GND
GND
STBY*
REMOTE SENSE(–)
Cin = Required 1500µF electrolytic
Cout = Required 330µF electrolytic
L 1 = Optional 1µH input choke
For technical support and more information, see inside back cover or visit www.ti.com
PT7615—5V
20-A Low-Voltage Programmable
Integrated Switching Regulator
Programming Information
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
20-A Programmable SIP Family
VID4=1
Vout
VID4=0
Vout
1.075V
1.100V
1.125V
1.150V
1.175V
1.200V
1.225V
1.250V
1.275V
1.300V
1.325V
1.350V
1.375V
1.400V
1.425V
1.450V
1.475V
1.500V
1.525V
1.550V
1.575V
1.600V
1.625V
1.650V
1.675V
1.700V
1.725V
1.750V
1.775V
1.800V
1.825V
1.850V
Product
Input
Voltage
Adjust
Method
Description
Output
Range
PT7709
5V
VID
5-Bit
1.3V– 3.5V
PT7708
3.3V
VID
4-Bit
1.3V– 2.05V
PT7615
5V
VID
5-Bit
1.075V–1.85V
PT7742
3.3V
Booster
—
—
PT7743
5V
Booster
—
—
Logic 0 = Pin 12 potential (Rem Sense Gnd)
Logic 1 = Open circuit (no pull-up resistors)
VID4 may not be changed while the unit is operating.
Specifications (Unless otherwise stated, Ta =25°C, Vin =5V, Cin =1,500µF, Cout =330µF, and Io =Iomax)
PT7615
Characteristics
Symbols
Conditions
Output Current
Io
T a = +60°C, 200 LFM, pkg N
T a = +25°C, natural convection
0.1
0.1
Input Voltage Range
Vin
Over I o range
4.5
—
5.5
Set-Point Voltage Tolerance
Vo tol
—
±10
±25
Temperature Variation
Regtemp
–40°C ≤Ta ≤ +85°C
—
±1.5
—
%Vo
Line Regulation
Regline
Over V in range
—
±5
±10
mV
Load Regulation
Regload
Over I o range
—
±5
±10
mV
Total Output Voltage Variation
∆Vo tol
Set-point, line, load
–40°C ≤Ta ≤ +85°C
—
±2
±3
%Vo
Efficiency
η
I o = 10A
Vo = 1.8V
Vo = 1.5V
Vo = 1.2V
—
—
—
87
84
81
—
—
—
%
Vo = 1.8V
Vo = 1.5V
Vo = 1.2V
—
—
—
82
79
75
—
—
—
%
mVpp
I o = 20A
Min
(1)
(1)
Typ
Max
Units
—
—
20
20
A
V
(2)
mV
Vo Ripple (pk-pk)
Vr
20MHz bandwidth
—
40
—
Transient Response
ttr
1A/µs load step, 10A and 20A
—
50
—
µSec
Vos
V o over/undershoot
—
±100
—
mV
—
32
—
A
300
350
400
kHz
—
—
0.3
Open (3)
0.8
—
V
Pin 5 to GND
2.0
-0.2
—
Pin 5 to GND
—
30
—
mA
—
15,000
µF
°C
Short Circuit Threshold
Isc (pk)
Switching Frequency
ƒs
Over V in range
STBY* Input Requirements
Input High Voltage
Input Low Voltage
Input Low Current
Referenced to GND
VIH
VIL
I IL
Standby Input Current
Iin standby
External Capacitance
Cout
Operating Temperature Range
Ta
Over V in Range
–40
—
+85
Storage Temperature
Ts
—
-40
—
+125
°C
330
(4)
(5)
mA
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
—
36
—
grams
Weight
—
Vertical/Horizontal
Flammability
—
Materials meet UL 94V-0
Notes: (1) ISR-will operate down to no load with reduced specifications.
(2) If the remote sense is not used, pin 12 must be connected to pin 13 for optimum output voltage accuracy.
(3) The STBY* control (pin 5) has an internal pull-up. If it is left open-circuit, the module will operate when input power is applied. A low-leakage (<1µA)
MOSFET must be used to control this pin. The open-circuit voltage may be as high as Vin.
(4) For operation below 0°C, Cin and Cout must have stable characteristics. Use either low ESR tantalum or Oscon® capacitors.
(5) See safe Operating Area curves or consult factory for the appropriate derating.
External Capacitors: The PT7615 require a minimum output capacitance of 330µF for proper operation. The PT7615 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 further
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 10ADC with a typical value of 1µH.
For technical support and more information, see inside back cover or visit www.ti.com
Typical Characteristics
PT7615—5V
20 Amp Low Voltage Programmable
Integrated Switching Regulator
PT7615 Characteristic Data, Vin =5.0
(See Note A)
PT7615 Safe Operating Area, Vin =5.0
Efficiency vs Output Current
(See Note B)
PT7615; Vo =1.2V
90.0
90
Efficiency - %
VOUT
1.8
1.5
1.2
70.0
60.0
Ambient Temperature (°C)
80
80.0
Airflow
70
200LFM
120LFM
60LFM
Nat conv
60
50
40
30
50.0
20
0
4
8
12
16
0
20
4
8
Iout (A)
12
16
20
Iout (A)
Ripple vs Output Current
PT7615; Vo =1.8V
50
90
Ripple - mV
VOUT
30
1.8
1.5
1.2
20
10
Ambient Temperature (°C)
80
40
70
Airflow
200LFM
120LFM
60LFM
Nat conv
60
50
40
30
0
20
0
4
8
12
16
20
0
Iout (A)
4
8
12
16
20
Iout (A)
Power Dissipation vs Output Current
8
6
Pd - Watts
VOUT
1.8
1.5
1.2
4
2
0
0
4
8
12
16
20
Iout (A)
Note A: All characteristic data in the above graphs has been developed from actual products tested at 25°C. This 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
Application Notes
PT7708/09, PT7615, PT7742/PT7743
Capacitor Recommendations for 20-A
Programmable Switching Regulators
Input Capacitors
The recommended input capacitance is determined by the
1.4 ampere minimum ripple current rating and 1500µF
minimum capacitance. Capacitors listed below must be
rated for a minimum of two times (2×) the input voltage
with +5V operation. Ripple current and ≤100mΩ ESR
(equivalent series resistance) 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 10-V rating are
recommended on the output bus, but only the AVX TPS
Series, Sprague 594/595 Series, or Kemet T495/T510
Series. These AVX, Sprague, and Kemet capacitors are
specified over other types due to their higher surge current,
excellent power dissipation and ripple current ratings.
As a caution, 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 also 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. Capacitors from
other vendors are available with comparible specifications.
The RMS ripple current rating and ESR (Equivalent Series
Resistance at 100kHz) are the critical parameters necessary
to insure both optimum regulator performance and long
capacitor life.
Table 1 Capacitors Characteristic Data
Capacitor
Vendor/
Series
Capacitor Characteristics
Quantity
Working
Voltage
Value(µF)
(ESR) Equivalent
Series Resistance
105°C Maximum
Ripple
Current(Irms)
Physical
Size(mm)
Input
Bus
Output
Bus
Panasonic
FC (SMT)
16V
35V
2200
330
0.038Ω
0.065Ω
2000mA
1205mA
18x16.5
12.5x16.5
1
1
1
EEVFC1C222N
EEVFC1V331LQ
FC (Radial)
10V
16V
560
1800
0.090Ω
0.032Ω
755mA
2000mA
10x12.5
18x15
1
1
EEUFC1A561
EEUFC1C182S
United
Chemi -Con
LFVSeries
25V
16V
16V
330
2200
470
0.084Ω
0.038Ω
0.084Ω÷2 =0.042Ω
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 (Radial)
SV (SMT)
10V
10V
330
330
0.025Ω÷4 =0.006Ω
0.02Ω÷4 =0.005Ω
>9800mA
>9800mA
10x10.5
10.3x12.6
4
4
N/R
(Note)
AVX
Tanatalum
TPS- Series
10V
10V
330
330
0.1Ω÷5 =0.02Ω
0.06Ω
3500mA
1826mA
7.3Lx
4.3Wx
4.1H
5
5
1
1
TPSV337M010R0100
TPSV337M010R0060
Sprague
Tantalum
595D/594D
10V
10V
330
680
0.045Ω÷4 =0.011Ω
0.09Ω
>4500mA
>1660mA
7.3L x
5.7W x
4.0H
5
2
1
1
594D337X0010R2T
595D687X0010R2T
(Surface Mount)
Kemet
Tantalum
T510/T495
Series
10V
330
0.035Ω
2000mA
5
1
510X337M010AS
10V
220
0.07Ω÷2 =0.035Ω
4.3Wx7.3L
x4.0H
>2000mA
6
2
T495X227M010AS
(Surface Mount)
Sanyo Poscap
TPB
10V
220
0.04Ω
3000mA
6
2
10TPB220M
(Surface Mount)
7.2L x
4.3W x
3.1H
1
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
Vendor Number
10SS330M
10SV330M
Application Notes continued
PT7708/09, PT7615
Using the Standby Function on 20-A
Programmable Switching Regulators
For applications requiring On/Off control of the output
voltage, the 20-A programmable regulators incorporate
a standby function. This feature may be used for powerup/shutdown sequencing, or to change the output voltage
while input power is applied. See related note: “Pin-Coded
Output Voltage Adjustment of 20-A Programmable Regulators”
Figure 1
6
7-11
5V
4 3 2 1
VID4 - VID0
The standby input must be controlled with an opencollector (or open-drain) discrete transistor (See Figure 1).
Table 1 gives the input requirements.
Table 1 Standby Control Input Requirements (1, 2)
Parameter
Min
Typ
Max
Enable
Disable
Istby (low)
Vstby (o/c)
2V
Open Cct. 1
–0.2V
0.8V
0.5mA
20-25
PT770x/PT761x
Vin
Synch
S T B Y Out
5
The standby function is provided by the STBY* control,
pin 5. If pin 5 is left open-circuit the regulator operates
normally, providing a regulated output whenever a valid
supply voltage is applied to Vin (pins 7-11) with respect to
GND (pins 13-19). Connecting pin 5 to ground 1 will set
the regulator output to zero volts 2. This places the regulator in standby mode, and reduces the input current to
typcially 30mA (60mA max). If a ground signal is applied
to pin 5 prior to power-up, the regulator output will be
held at zero volts during the period that input power is
applied.
26
Rem Sns (+)
GND
27
V o =3.3V
Vo
Rem Sns (–)
13-19
12
+
L
O
A
D
+
C in
C out
Q1
BSS138
Inhibit
COM
COM
Turn-On Time: Turning Q1 in Figure 1 off, removes the
low-voltage signal at pin 5 and enables the output.
Following a delay of approximately 10ms, the regulator
output voltage rises to full regulation within 30ms 3.
Figure 2 shows the typical output voltage waveform of a
PT7709 following the turn-off of Q1 at time t =0 secs.
The output voltage is set to 3.3V by connecting VID0
(pin 1), VID2 (pin 3), and VID3 (pin 4) to the ‘Rem
Sns (–)’, (pin 12)*. The waveform was measured with a
+5V input source voltage, and 10-A resistive load.
Figure 2
Vin
Notes:
1. The Standby input must be controlled using an opencollector (or open-drain) discrete transistor. Do Not use a
pull-up resistor. The control input has an open-circuit
voltage equal to Vin. To set the regulator output to zero,
the control pin must be “pulled” to less than 0.8Vdc with a
0.5mA sink to ground.
Vo (2V / Div)
Iin 10A / Div)
2. When placed in the standby mode, the regulator output
discharges the output capacitance with a low impedance to
ground.
3. The turn-off time of Q1, or rise time of the standby input
is not critical with these regulators. Turning Q1 off slowly,
over periods up to 100ms, will not affect regulator operation.
A slow turn-off time will merely increase both the initial
delay and rise-time of the output voltage.
0
5
10
15
20
25
t (milli - secs)
* Consult the data sheet for details on other VID codes.
For technical support and more information, see inside back cover or visit www.ti.com
30
Application Notes
PT7708/09, PT7615
Pin-Coded Output Voltage Adjustment of
20-A Programmable Regulators
4. If active devices are used to ground the voltage control
pins, low-level open drain MOSFET devices should be
used over bipolar transistors. The inherent Vce(sat) in
bipolar devices introduces errors in the device’s internal
divider network. Discrete transistors such as the BSS138,
2N7002, or IRLML2402 are examples of appropriate
devices.
The 20-A family of programmable ISRs incorporate a pincoded control to adjust the output voltage. This feature
uses the control pins VID0–VID4 (pins 1–6). When
the control pins are left open-circuit, the ISR output
regulates at its default output voltage. Each control pin
is internally connected to a precision resistor, which
when grounded applies a weighted change to the output
voltage. By selectively grounding VID0–VID4, the output
voltage of these ISRs can be programmed in incremental
steps over the module’s output voltage range. The program
codes and output voltage range offered by these ISRs are
compatible with the Voltage ID specifications defined by
Intel Corporation for VRMs (voltage regulator modules). The codes are used by both the Pentium® and
Athlon® microprocessors. Refer to Figure 1 for the
connection schematic, and the respective device Data Sheet
for the programming code information.
Active Voltage Programming:
Special precautions should be taken when making changes
to the voltage control progam code while the unit is
powered. It is highly recommended that the ISR be either
powered down or held in standby. Changes made to the
program code while Vout is enabled induces high current
transients through the device. This is the result of the
electrolytic output capacitors being either charged or
discharged to the new output voltage set-point. The
transient current can be minimized by making only incremental changes to the binary code, i.e. one LSB at a
time. A minimum of 100µs settling time between each
program state is also recommended. Making nonincremental changes to VID3 or VID4 while the output
is enabled is discouraged. The transients induced can
overstress the device. If the program code cannot be
asserted priot to power-up, pull pin 5 (STBY) control to
GND during the period that the input voltage is applied
to Vin. Releasing pin 5 will then allow the device to perform a soft-start to the programmed voltage. For more
information on the use of the Standby function, consult
the related application note, “Using the Standby Function
on 20-A Programmable Switching Regulators”
Notes:
1. The programming convention is as follows:
Logic 0:
Logic 1:
Connect to pin 12 (Remote Sense Ground).
Open circuit/open drain (See notes 2, & 4)
2. Do not connect pull-up resistors to the voltage
programming pins.
3. Use pin 12 (Remote Sense Ground) as the logic “0”
reference. While the regular ground (pins 13-19) can also
be used for programming, doing so will degrade the load
reglation of the product. If the remote sense ground is
not used, pin 12 must be connected to pin 13 for
optimum output voltage accuracy.
Figure 1
6 4 3 2 1
26
VID4 - VID0
+5V
7-11
1µH
(Optional)
PT770X/PT761X
Vin
STBY
5
Cin
SNS(+)
Synch
Out
27
GND
13-19
+
STBY
COM
For technical support and more information, see inside back cover or visit www.ti.com
20-25
Vo
SNS(-)
12
Cout
+
L
O
A
D
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