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dc1717afa

DEMO MANUAL DC1717A

Quick start proceDure

Refer to the Figure 3 for proper measurement equipment 

setup and follow the procedure below: 
Initially, the LTC4417 should be disabled by:

• 

placing the jumper 

JP2

 (EN) header in the OFF position, 

and

• 

placing the jumper 

JP3

  (

SHDN

) header in the OFF  

position

Connecting the auxiliary power source (6V to 24V) to 

the DC1717A (AVI and GND turrets) lights the green LED 

(LDO-D12) indicating the presence of aux5V supply 

for powering logic.
With power off, connect three power supplies with output 

voltages of 12V, 5V, and 8V to corresponding DC1717A 

turrets or banana jacks V1(+12V), V2(+5V), V3(+8V), 

and GND.

Connect 6Ω load resistor (30W) to the DC1717A output 

turret or banana jack (VOUT). Do not use an electronic 

load in constant current mode.
Turn on three power supplies. No additional LEDs should 

light.
Change the jumper 

JP3

  (

SHDN

) header position from 

OFF to ON. Three LEDs (

VALID1

VALID2

, and 

VALID3

validating the input rail voltages should light. 
Placing the jumper 

JP2

 (EN) in the ON position turns on 

the LTC4417 powering the load with 12V (2.0A). In an 

initial power up the LTC4417 uses a fixed slew rate for the 

output voltage, which should be not larger than 5V/ms.
The prioritizing function is demonstrated by simply turning 

off one or two of the V1, V2 and V3 supplies. The output 

will be powered from the remaining supply of the high-

est priority. V1, V2 and V3 may be adjusted up and down 

beyond ±20% to invalidate a given input.  

RESISTIVE

LOAD

12V

POWER

SUPPLY

5V

POWER

SUPPLY

8V

POWER

SUPPLY

Figure 3

Summary of Contents for DC1717A

Page 1: ...G SOURCE Sourcing VS VG Clamp Voltage VOUT 11V I 10µA 5 8 6 6 7 V ΔVG SINK Sinking VS VG Clamp Voltage VOUT 11V I 10µA 4 5 5 2 6 V ΔVG OFF G1 to G3 Off VS VG Threshold V1 V2 V3 2 8V VOUT 2 6V G1 to G3 Rising Edge 0 12 0 35 0 6 V ΔVG SLEW ON G1 to G3 Pull Down Slew Rate VOUT 11V CGATE 10nF 4 9 20 V µs ΔVG SLEW OFF G1 to G3 Pull Up Slew Rate VOUT 11V CGATE 10nF 7 5 13 22 V µs IGATE LOW G1 to G3 Low ...

Page 2: ...sis is 6 and can be changed to 3 by moving the JP1 jumper to the 30mV position The controller s break before make switching method prevents cross conduction between input channels and reversecurrentfromtheoutputcapacitorintotheselected input supply Each channel s control circuit of the LTC4417 has a REV comparator which monitors the connecting input supply and output load voltage The REV comparato...

Page 3: ... VALID pins at 0 7V but otherwise leaves the LTC4417 operating autonomously The following design considerations and equations dem onstrate the interrelation of the main component values and transient parameters in the rail transitions when the output voltage exceeds 0 7V The variables CS and RS used in the design equations correspond to the following board components C20 R23 for V1 12V channel C21...

Page 4: ...e Use CL INIT and RS No Is recalculated CL lower than initial CL INIT As shown in the equation 3 the use of external slew rate control will add additional delay to the total switchover time Unfortunately the actual components cannot be chosen until the load capacitance is known This circular issue can only be resolved through an iterative process TheprocessstartsbycalculatingtheCLOAD MIN assuming ...

Page 5: ...nal to the LTC4417 Optional R33 may be added as a pull up to the auxiliary 5V power supply SHDN pulled up by 2μA internal to the LTC4417 Optional R36 may be added as a pull up to the auxiliary 5V power supply CAS used to cascade a second DC1717A Connect the CAS turret of the high priority DC1717A to the EN turret of the lower priority DC1717A Grounds must be connected in common JP1 HYS Add 30mV fi...

Page 6: ... 30W to the DC1717A output turret or banana jack VOUT Do not use an electronic load in constant current mode Turn on three power supplies No additional LEDs should light Change the jumper JP3 SHDN header position from OFF to ON Three LEDs VALID1 VALID2 and VALID3 validating the input rail voltages should light Placing the jumper JP2 EN in the ON position turns on the LTC4417 powering the load with...

Page 7: ...Q3 DUAL P CHAN 40V POWERPAK1212 8 DUAL VISHAY Si7905DN T1 GE3 19 0 Q4 Q5 Q6 Q7 Q8 Q9 MOSFET P CHAN 40V FDD4685 DPAK OPT 20 1 Q10 XTOR N CHAN SOT23 DIODE INC MMBTA42 7 F 21 1 Q11 XTOR N CHAN SOT23 DIODE INC MMBT3904 7 F 22 1 R4 RES CHIP 1 69M 0 125W 1 0805 VISHAY CRCW08051M69FKEA 23 3 R5 R8 R12 RES CHIP 69 8k 0 125W 1 0805 VISHAY CRCW080569K8FKEA 24 3 R6 R9 R13 RES CHIP 130k 0 125W 1 0805 NIC NRC10...

Page 8: ...ROPRIETARY TO LINEAR TECHNOLOGY AND SCHEMATIC SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS SCALE NONE www linear com 3 DEMO CIRCUIT 1717A Thursday July 23 2015 1 2 PRIORITIZED POWERPATH CONTROLLER N A LTC4417CUF KIM T VLAD O SIZE DATE IC NO REV SHEET OF TITLE APPROVALS PCB DES APP ENG TECHNOLOGY Fax 408 434 0507 Milpitas CA 95035 Phone 408 432 1900 1630 McCarthy Blvd LTC Confidential For Customer...

Page 9: ...APPLICATION COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SCHEMATIC SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS SCALE NONE www linear com 3 DEMO CIRCUIT 1717A Thursday July 23 2015 2 2 PRIORITIZED POWERPATH CO...

Page 10: ...INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE EXCEPT TO THE EXTENT OF THIS INDEMNITY NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES The user assumes all responsibility and liability for proper and safe handling of the goods Further the user releases LTC from all claims arising from the handling or use of the...

Page 11: ...Mouser Electronics Authorized Distributor Click to View Pricing Inventory Delivery Lifecycle Information Analog Devices Inc DC1717A ...

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