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PT6930 Series
25 Watt 5V Input Dual Output Integraged Switching Regulator

SLTS062A
(Revised 6/30/2000)

· Dual Outputs:
+3.3V/2.5V +3.3V/1.5V +3.3V/1.8V

· · · · · · ·
Patent pending on package assembly

Adjustable Output Voltage Remote Sense (both outputs) Standby Function Over-T emperature Protection Soft-Start Internal Sequencing 23-pin ExcaliburTM Package

The PT6930 is a new series of 25W dual output ISRs designed to power the latest generation DSP chips. Both output voltages are independently adjustable with external resistors. In addition, the second output voltage of the PT6931 can be selected for either 2.5V or 1.8V to accommodate the next generation of DSP chips. The internal power sequencing of both outputs meet the requirements of TI's `C6000 series DSPs.

Pin-Out Information
Pin Function
1
V2SENSE

Ordering Information
Pin
13 14 15 16 17 18 19 20 21 22 23

Standard Application
STBY
3 22 1 18-21

Function
V1out V1out V1out V1 Adjust
Do Not Connect

V1 Remote Sense
Do Not Connect

2 3
V1 O U T V2 O U T

V1SENSE

STBY Vin Vin Vin GND GND GND GND GND V1out

4 5 6 7 8 9 10 11 12

PT6931J = +3.3 Volts J +2.5/1.8 Volts PT6932J = +3.3 Volts J +1.5/1.2 Volts J PT6933J = +3.3 Volts +1.8/1.2 Volts

VIN

4,5,6

PT6930
7-11 16 23

12-15

V2out V2out V2out V2out V2 Remote Sense V2 Adjust*

+ C1 + C2 GND
C 1 = Req'd 560µF electrolytic C 2 = Req'd 330µF electrolytic C 3 = Optional 100µF electrolytic
(1) (1)

C3

PT Series Suffix (PT1234X)
Case/Pin Configuration Vertical Through-Hole Horizontal Through-Hole Horizontal Surface Mount

GND

N A C

Specifications
Characteristics (Ta= 25°C unless noted) Output Current Symbols Io

*Note:V1out and V2out are adjustable, and can be pin-strapped to produce at least one alternative common bus voltage. Consult the factory for more information. Conditions Ta = +60°C, 200 LFM, pkg N V1 = 3.3V V2 = 2.5V V2 = 1.8V V2 =1.5V V2 = 1.2V V1 =3.3V V2 =2.5V V2 = 1.8V V2 =1.5V V2 = 1.2V Min 0.1 0 0 0 0 0.1 0 0 0 0 4.5 Vo-0.1 V1 =3.3V V2 =2.5V V1 = 3.3V V2 = 2.5V V1 = 3.3V V2 = 2.5V -- -- -- -- -- -- -- -- -- -- 475 -40 (4) -40 --
(2)

(For dimensions and PC board layout, see Package Styles 1320 and 1330.)

PT6930 SERIES
Typ -- -- -- -- -- -- -- -- -- -- -- -- ±7 ±7 ±17 ±4 50 25 25 60 60 75 600 -- -- 29 Max 5.5 2.2 1.75 1.45 1.2 6.0 2.2 1.75 1.45 1.2 5.5 Vo+0.1 ±17 ±13 ±33 ±10 -- -- -- -- -- -- 725 +85 (5) +125 --
(3) (3) (3) (3) (3)

Units

A

Ta = +25°C, natural convection

A

Input Voltage Range Output Voltage T olerance Line Regulation Load Regulation Vo Ripple/Noise Transient Response with C2 = 330µF Efficiency Switching Frequency Absolute Maximum Operating T emperature Range Storage T emperature Weight

Vin Vo Regline Regload Vn ttr Vos o Ta Ts --

0.1A Io Imax Vin = +5V, Io = Imax, both outputs 0°C Ta +65°C 4.5V Vin 5.5V, Io = Imax Vin = +5V, 0.1 I o I max Vin = +5V, Io = Imax

V V V mV mV µSec mV % kHz °C °C grams

Io step between 0.5xI max and Imax Vo over/undershoot V1 = 3.3V V2 = 2.5V Vin = +5V, Io = 4A total 4.5V Vin 5.5V 0.1A Io Imax -- -- Vertical/Horizontal

Notes: (1) (2) (3) (4) (5)

The PT6930 series requires a 560µF electrolytic capacitor on the input and a 330µF electrolytic capacitor on the output for proper operation in all applications. 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. Iomax listed for each output assumes the maximum current drawn simultaneously on both outputs. Consult the factory for the absolute maximum. For operating temperatures below 0°C, use tantalum type capacitors on both the input and output. See Safe Operating Area curves for appropriate derating.

For technical support and more information, see inside back cover or visit www.ti.com/powertrends

PT6930 Series
25 Watt 5V Input Dual Output Integraged Switching Regulator

Typical Characteristics

PT6931, V2out = 2.5V, I2out = 2.2A
Total Efficiency vs I1out
90 80

(See Note A)

Efficiency (%)

70

Vin
4.5V 5.0V 5.5V

60

50

40 0 1 2 3 4 5 6

Output Current (A)

Total Power Dissipation vs I 1out
8

6

PDiss (Watts)

Vin
4 5.5V 5.0V 4.5V

2

0 0 1 2 3 4 5 6

Output Current (A)

40

V1out Ripple vs I1out

30

Ripple (mV)

Vin
20 5.5V 5.0V 4.5V

10

0 0 1 2 3 4 5 6

Output Current (A)

90.0 80.0

Safe Operating Area vs I1out (See Note B)

Ambient Temperature ( C)

70.0 60.0 50.0 40.0 30.0 20.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0

Vout 200LFM 120LFM 60LFM Nat conv

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 data for the ISR. Note B: SOA curves represent operating conditions at which internal components are at or below the manufactuer's maximum rated operating temperatures.

For technical support and more information, see inside back cover or visit www.ti.com/powertrends

Application Notes
PT6920/PT6930 S eries

Adjusting the Output Voltage of the PT6920 and PT6930 Dual Output Voltage ISRs
Each output voltage from the PT6920 and PT6930 series of ISRs can be independantly adjusted higher or lower than the factory trimmed pre-set voltage. V1 (the voltage at V1out), or V2 (the voltage at V2out) may each be adjusted either up or down using a single external resistor 2. T able 1 gives the adjustment range for both V1 and V2 for each model in the series as Va(min) and Va(max). Note that V2 must always be lower than V1 3. V1 Adjust Up: T increase the output, add a resistor o R4 between pin 16 (V1 Adjust) and pins 7-11 (GND) 2. V1 Adjust Down: Add a resistor (R3), between pin 16 (V1 Adjust) and pin 1 (V1 Remote Sense) 2. V2 Adjust Up: Add a resistor R2 between pin 23 (V2 Adjust) and pins 7-11 (GND) 2. V2 Adjust Down: Add a resistor (R1) between pin 23 (V2 Adjust) and pin 22 (V2 Remote Sense) 2. Refer to Figure 1 and T able 2 for both the placement and value of the required resistor. Notes: 1. The output voltages, V1out and V2out, may be adjusted independantly. 2. Use only a single 1% resistor in either the (R3) or R4 location to adjust V1, and in the (R1) or R2 location to adjust V2. Place the resistor as close to the ISR as possible. 3. V2 must always be at least 0.2V lower than V1. 4. V2 on both the PT6921 and PT6931 models may be adjusted from 2.5V to 1.8V by simply connecting pin 22 (V2 Remote Sense) to pin 23 (V2 Adjust). For more details, consult the data sheet.

5. If V1 is increased above 3.3V, the minimum input voltage to the ISR must also be increased. The minimum required input voltage must be (V1 + 1.2)V or 4.5V, whichever is greater. Do not exceed 5.5V 6. Never connect capacitors to either the V1 Adjust or V2 Adjust pins. Any capacitance added to these control pins will affect the stability of the respective regulated output. 7. Adjusting either voltage (V1 or V2) may increase the power dissipation in the regulator, and correspondingly change the maximum current available at either output. Consult the factory for application assistance. The adjust up and adjust down resistor values can also be calculated using the following formulas. Be sure to select the correct formula parameter from T able 1 for the output and model being adjusted. Ro (Va ­ 1) (R1) or (R3) = ­ Rs k Vo ­ Va R2 or R4 Where: = Vo Va Ro Rs Ro Va ­ Vo ­ Rs k

= Original output voltage, (V1 or V2) = Adjusted output voltage = The resistance value from T able 1 = The series resistance from T able 1

Table 1 PT6920 ADJUSTMENT RANGE AND FORMULA PARAMETERS
Output Bus Series Pt # Standard Case Excalibur Case Adj. Resistor Vo(nom) Va(min) Va(max) Ro (k) Rs (k) V1 out PT6921/22 PT6931/32 (R3)/R4 3.3V 2.3V 3.6V 12.1 12.1 PT6921 PT6931 (R1)/R2 2.5V 1.8V 3.0V 10.0 11.5 V2 out PT6922 PT6932 (R1)/R2 1.5 1.2 3.0 9.76 6.49

Figure 1

22 V 2 (sns) 4,5,6 Vin

1 V 1 (sns) V 2 out 18 - 21

V 2 out V 1 out (R1)
+ + L O A D L O A D

Vin

PT6920
V 1 out 12 - 15 GND 7 - 11 Vo 2 (adj) Vo1 (adj) 23 16

STBY 3

+

(R3) Adj Down

C1 R4 Adjust Up COM Adjust V1out R2

C2

C3

COM Adjust V2out

For technical support and more information, see inside back cover or visit www.ti.com/powertrends

Application Notes continued
PT6920/PT6930 S eries

Table 2 PT6920/PT6930 ADJUSTMENT RESISTOR VALUES
Output Bus V1 out Series Pt# Standard Case PT6921/6922 Excalibur Case PT6931/6932 Adj Resistor (R3)/R4 Vo(nom) 3.3Vdc Va(req'd) 1.2 1.25 1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 1.7 1.75 1.8 1.85 1.9 1.95 2.0 2.05 2.1 2.15 2.2 2.25 2.3 2.35 2.4 2.45 2.5 2.55 2.6 2.65 2.7 2.75 2.8 2.85 2.9 2.95 3.0 3.05 3.1 3.15 3.2 3.25 3.3 3.4 3.5 109.0k See Note 5 48.4k (3.6)k (5.1)k (6.7)k (8.5)k (10.6)k (12.9)k (15.6)k (18.6)k (22.2)k See Note 3 (26.4)k (31.5)k (37.6)k (45.4)k (55.3)k (68.6)k (87.1)k (115.0)k (161.0)k (254.0)k (532.0)k 189.0k 88.5k 55.2k 38.5k 28.5k 21.8k 17.1k 13.5k 10.7k 8.5k (0.0)k (1.6)k (3.5)k (5.8)k (8.5)k (11.8)k (16.0)k (21.4)k (28.5)k (38.5)k (53.5)k (78.5)k (129.0)k (279.0)k 189.0k 91.1k 58.6k 42.3k 32.6k 26.0k 21.4k 17.9k 15.2k 13.0k 11.3k 9.8k 8.5k 7.5k 6.5k 5.7k 5.0k 4.4k 3.8k 3.3k 2.8k 2.4k 2.0k 1.6k 1.3k 1.0k 0.7k 0.5k 0.2k 0.0k V2 out PT6921 PT6931 (R1)/R2 2.5Vdc PT6922 PT6932 (R1)/R2 1.5Vdc (0.0)k (3.3)k (8.2)k (16.3)k (32.6)k (81.4)k

3.6 28.2k R1/R3 = (Blue) R2/R4 = Black

For technical support and more information, see inside back cover or visit www.ti.com/powertrends

Application Notes
PT6920/PT6930 S eries

Using the Standby Function on the PT6920 and PT6930 Dual Output Voltage Converters
Both output voltages of the 23-pin PT6920/6930 dual output converter may be disabled using the regulator's standby function. This function may be used in applications that require power-up/shutdown sequencing, or wherever there is a requirement to control the output voltage On/Off status with external circuitry. The standby function is provided by the STBY* control, pin 3. If pin 3 is left open-circuit the regulator operates normally, and provides a regulated output at both V1out (pins 12­15) and V2out (pins 18­21) whenever a valid supply voltage is applied to Vin (pins 4, 5, & 6) with respect to GND (pins 7-11). If a low voltage2 is then applied to pin-3 both regulator outputs will be simultaneously disabled and the input current drawn by the ISR will typcially drop to less than 30mA (50mA max). The standby control may also be used to hold-off both regulator outputs during the period that input power is applied. The standby pin is ideally controlled using an open-collector (or open-drain) discrete transistor (See Figure 1). It may also be driven directly from a dedicated TTL3 compatible gate. Table 1 provides details of the threshold requirements.
Table 1 Inhibit Control Thresholds 2,3 Parameter Min Max
Enable (VIH) Disable (VIL) 1.8V ­0.1V Vin 0.8V

Figure 1

22 V 2 (sns) 4,5,6 Vin

1 V 1 (sns) V 2 out 18 - 21

V 2 out V 1 out

V in

PT6921
V 1 out 12 - 15 GND 7 - 11 Vo 2 (adj) 23 V 0 1 (adj) 16

STBY

+ C1

3

+ C2 C3

+

COM
Q1 BSS138

COM

Inhibit
+5V V in

Turn-On Time: T urning Q1 in Figure 1 off removes the lowvoltage signal at pin 3 and enables both outputs from the PT6920/6930 regulator. Following a delay of about 5­10ms, V1out and V2out rise together until the lower voltage, V2out, reaches its set output. V1out then continues to rise until both outputs reach full regulation voltage. The total power-up time is less than 15ms, and is relatively independant of load, temperature, and output capacitance. Figure 2 shows waveforms of the input current Iin, and output voltages V1out and V2out, for a PT6921 (3.3V/2.5V). The turn-off of Q1 corresponds to t =0 secs. The waveforms were measured with a 5Vdc input voltage, and with resistive loads of 5.5A and 2.2A at the V1out and V2out outputs respectively.

Notes: 1. The Standby/Inhibit control logic is similar for all Power Trends' modules, but the flexibility and threshold tolerances will be different. For specific information on this function for other regulator models, consult the applicable application note. 2. The Standby control pin is ideally controlled using an open-collector (or open-drain) discrete transistor and requires no external pull-up resistor. T disable the o regulator output, the control pin must be pulled to less than 0.8Vdc with a low-level 0.5mA sink to ground. 3. The Standby input on the PT6920/6930 series may be driven by a differential output device, making it directly compatible with TTL logic. The control input has an internal pull-up to the input voltage Vin. A voltage of 1.8V or greater ensures that the regulator is enabled. Do not use devices that can drive the Standby control input above 5.5V or Vin.

Figure 2
V1 (2V/Div) V2 (2V/Div)

Iin (4A/Div)

0

2

4

6

8

10

12

14

t (milli - secs)

For technical support and more information, see inside back cover or visit www.ti.com/powertrends

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