Datel 20A manual Trim Equations, USQ-1.2/20-D48

Page 6

USQ Series

2 0 A , S I N G L E O U T P U T D C / D C C O N V E R T E R S

 

 

Standard USQ's have a "positive trim" where a single resistor connected from the Trim pin (pin 6) to the +Sense (pin 7) will increase the output voltage.

A resistor connected from the Trim Pin (pin 6) to the –Sense (pin 5) will decrease the output voltage. DATEL also offers a "negative trim" function (D suffix added to the part number). Contact DATEL for information on negative trim devices.

Trim adjustments greater than the specified +10%/–20% can have an adverse affect on the converter’s performance and are not recommended. Excessive voltage differences between VOUT and Sense, in conjunction with trim adjustment of the output voltage, can cause the overvoltage protection circuitry to activate (see Performance Specifications for overvoltage limits).

Temperature/power derating is based on maximum output current and volt- age at the converter's output pins. Use of the trim and sense functions can cause output voltages to increase, thereby increasing output power beyond the USQ's specified rating, or cause output voltages to climb into the output overvoltage region. Therefore:

(VOUT at pins) x (IOUT) rated output power

The Trim pin (pin 6) is a relatively high impedance node that can be suscep- tible to noise pickup when connected to long conductors in noisy environ- ments. In such cases, a 0.22µF capacitor can be added to reduce this long lead effect.

1

–INPUT

+OUTPUT

8

 

 

 

 

 

 

 

 

+SENSE

7

 

 

 

2

ON/OFF

TRIM

6

 

CONTROL

LOAD

 

 

RTRIM UP

 

 

 

 

 

–SENSE

5

 

 

 

3

+INPUT

 

4

 

–OUTPUT

 

 

 

 

 

Figure 5. Trim Connections To Increase Output Voltages Using Fixed Resistors

1

–INPUT

+OUTPUT

8

 

 

 

 

 

 

 

 

+SENSE

7

 

 

 

2

ON/OFF

TRIM

6

 

CONTROL

LOAD

 

 

RTRIM DOWN

 

 

 

 

 

–SENSE

5

 

 

 

3

+INPUT

 

4

 

–OUTPUT

 

 

 

 

 

Trim Equations

USQ-1.2/20-D48

RT UP (kΩ) =

1.308(VO – 0.793)

 

 

–1.413

RTDOWN (kΩ) =

 

1.037

 

–1.413

 

 

 

1.2 – VO

 

 

 

 

VO – 1.2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

USQ-1.5/20-D48

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RT UP (kΩ) =

 

6.23(VO – 1.226)

 

–10.2

RTDOWN (kΩ) =

7.64

 

–10.2

 

VO – 1.5

1.5 – VO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

USQ-1.8/20-D48

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RT UP (k

) =

 

7.44(VO – 1.226)

 

–10.2

RTDOWN (k

) =

 

 

 

 

 

 

9.12

 

–10.2

 

VO – 1.8

 

 

 

 

 

 

 

1.8 – VO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

USQ-2.5/20-D48

 

 

 

 

 

 

 

 

 

 

 

RT UP (kΩ) =

 

10(VO – 1.226)

 

–10.2

RTDOWN (kΩ) =

 

12.26

 

–10.2

 

 

 

 

 

 

 

 

VO – 2.5

 

2.5 – VO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

USQ-3.3/20-D48

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RT UP (kΩ) =

 

13.3(VO – 1.226)

 

–10.2

RTDOWN (kΩ) =

 

 

16.31

 

–10.2

 

VO – 3.3

 

3.3 – VO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

USQ-5/20-D24, -D48

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RT UP (kΩ) =

 

20.4(VO – 1.226)

 

–10.2

RTDOWN (kΩ) =

 

 

 

25.01

 

–10.2

 

VO – 5

 

5 – VO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

USQ-12/8.3-D24, -D48

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RT UP (kΩ) =

 

49.6(VO – 1.226)

 

–10.2

RTDOWN (kΩ) =

 

 

 

 

 

60.45

 

–10.2

 

VO – 12

 

12 – VO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

USQ-15/6.7-D24, -D48

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RT UP (kΩ) =

 

62.9(VO – 1.226)

 

–10.2

RTDOWN (kΩ) =

 

 

 

 

 

 

76.56

 

–10.2

 

VO – 15

 

15 – VO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

USQ-18/5.6-D24, -D48

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RT UP (kΩ) =

 

75.5(VO – 1.226)

 

–10.2

RTDOWN (kΩ) =

92.9

 

–10.2

 

VO – 18

 

18 – VO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

USQ-24/4.2-D24, -D48

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RT UP (kΩ) =

 

101(VO – 1.226)

 

–10.2

RTDOWN (kΩ) =

124.2

 

–10.2

 

VO – 24

 

24 – VO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Note: Resistor values are in k. Adjustment accuracy is subject to resistor tolerances and factory-adjusted output accuracy. VO = desired output voltage.

Figure 6. Trim Connections To Decrease Output Voltages Using Fixed Resistors

6

Image 6
Contents  Outstanding thermal-derating  Output current to 20 Amps Features Fully isolated, 1500Vdc guaranteed  UL1950/EN60950 Basic insulation approvalsPerformance Specifications and Ordering Guide Case C33Performance/Functional Specifications Filtering, Input Ripple Current, and Output Noise Removal of Soldered USQs from PCBsInput Source Impedance Input Overvoltage ShutdownOn/Off Control Input FusingStart-Up Time Current LimitingTrim Equations USQ-1.2/20-D48Trim-Up Resistance vs. Percentage Increase in Output Voltage USQ-12 Trim-Up Resistance vs. % Increase Vout Floating Outputs Negative-Trim Units D SuffixModel Trim Up Remote SensePerformance Specifications Dynamic Load Response and Switching FrequencySwitching Frequency min./typ./max. kHz Load Step = 50 to 75% of Iout Max Peak Deviation, typTBD Typical Performance Curves for 1.2VOUT ModelsTypical Performance Curves for 1.5VOUT Models Typical Performance Curves for 1.8VOUT Models Typical Performance Curves for 2.5VOUT Models Typical Performance Curves for 3.3VOUT Models Typical Performance Curves for 5VOUT Models Start-Up from VINUSQ Models Typical Performance Curves for 12VOUT Models USQ-12/8.3-D24 Output Current vs. Ambient Temperature Typical Performance Curves for 15VOUT Models Typical Performance Curves for 24VOUT Models Mail datel.sarl@datel.com Output TrimDatel S.A.R.L. Montigny Le Bretonneux, France Tel Datel GmbH München, Germany Tel