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UG-456 

Evaluation Board User Guide 

 

Rev. 0 | Page 4 of 12 

MEASURING EVALUATION BOARD PERFORMANCE 

Output Voltage Ripple 

To observe the output voltage ripple, place an oscilloscope probe 
tip at the T3 terminal and connect the probe ground lead at the 
negative (−) the T4 terminal. Set the oscilloscope to an ac-coupled, 
100 mV/division and 2 µs/division time base.  

Switching Waveform 

To observe the switching waveform with an oscilloscope, place 
the oscilloscope probe tip at the end of the inductor that is 
connected to the SW pin with the probe ground at Terminal T4, 
PGND. Set the scope to dc, 5 V/division, and 2 µs/division time 
base. Alternate the switching waveform between 0 V and 
approximately the input voltage. 

Measuring Load Regulation 

Measure the load regulation by increasing the load at the output 
and looking at the change in the output voltage. To minimize voltage 
drop, use short low resistance wires, especially for heavy loads. 

Measuring Line Regulation 

Vary the input voltage and examine the change in the output 
voltage. In PWM mode, ensure that the output voltage ripple is 
small (<50 mV); however, in pulse skip mode, the output voltage 
ripple can be as large as 100 mV. 

Measuring Efficiency 

The efficiency, η, is measured by comparing the input power with 
the output power. 

IN

IN

OUT

OUT

I

V

I

V

×

×

=

η

 

Measure the input and output voltages as close as possible to the 
input and output capacitors to reduce the effect of IR drops. 

Inductor Current 

By removing one end of the inductor from its pad and connecting a 
current loop in series with it, the inductor current can be measured. 
Once this is done, a current probe can be used to measure the 
current flowing through the current loop. 

Line Transient Response 

Generate a step input voltage (V

IN

) and observe the behavior  

of the output voltage, with an oscilloscope.  

Load Transient Response

 

Generate a load current transient at the output, V

OUT

, and 

observe the output voltage response with an oscilloscope.  
Use a current probe attached to the wire between the output 
and the load to visualize the current transient. 

Loop Stability Measurement 

Closed-loop response can be measured using a network analyzer. 
To measure the loop response, the IN and OUT headers are 
available. 
 

 

Содержание ADP2442-EVALZ

Страница 1: ...valuation board is a complete dc to dc switching regulator design based on the ADP2442 a configurable 1 A synchronous step down dc to dc regulator The ADP2442 is a synchronous step down dc to dc switching regulator that uses a current mode pulse width modulation PWM control scheme The ADP2442 can be configured for pulse skip mode at light load or forced PWM mode The power switch and synchronous re...

Страница 2: ...e Evaluation Board 3 Powering Up the Evaluation Board 3 Measuring Evaluation Board Performance 4 Modifying the Evaluation Board 5 Changing the Output Voltage 5 Changing the Switching Frequency 5 Typical Performance Characteristics 6 Evaluation Board Schematic and Artwork 8 Ordering Information 10 Bill of Materials 10 REVISION HISTORY 11 12 Revision 0 Initial Version ...

Страница 3: ...ore powering the ADP2442 EVALZ evaluation board Before connecting a load to the output of the evaluation board ensure that the output voltage does not exceed the maximum operating voltage range of the load Enabling and Disabling the DC to DC Switching Regulator In the evaluation board a voltage divider is used to generate an enable signal for the IC As soon as voltage is applied to VIN 24 V IC is ...

Страница 4: ...in the output voltage In PWM mode ensure that the output voltage ripple is small 50 mV however in pulse skip mode the output voltage ripple can be as large as 100 mV Measuring Efficiency The efficiency η is measured by comparing the input power with the output power IN IN OUT OUT I V I V η Measure the input and output voltages as close as possible to the input and output capacitors to reduce the e...

Страница 5: ...etermined calculate the value of the top resistor R2 by FB FB OUT V V V R3 R2 For example to set the output regulation voltage of the ADP2442 EVALZ to 3 3 V calculate the R2 and R3 values as shown in the following equations kΩ 10 μA 60 V 0 6 STRING I FB V R3 Ω Ω k 45 3 0 6V V 0 6 V 3 3 k 10 FB FB OUT V V V R3 R2 When the output voltage of the ADP2442 EVALZ is changed the output capacitors C7 and C...

Страница 6: ...A 0 10 20 30 40 50 60 70 80 90 100 0 01 0 1 1 EFFICIENCY LOAD A VIN 12V VIN 24V VIN 36V 10949 005 0 10 20 30 40 50 60 70 80 90 100 0 01 0 1 1 EFFICIENCY VIN 12V VIN 24V VIN 36V 10949 006 LOAD A LOAD A 10949 007 4 980 4 985 4 990 4 995 5 000 5 005 5 010 5 015 5 020 5 025 5 030 5 035 5 040 0 0 2 0 4 0 6 0 8 1 0 1 2 V OUT V VIN 12V VIN 24V VIN 36V 10949 008 4 97 4 98 4 99 5 00 5 01 5 02 5 03 5 04 5 0...

Страница 7: ...200µs A CH4 720mA 1 4 2 T 71 2 B W CH4 500mA Ω LOAD STEP 500mA SW SW 10949 011 VOUT CH1 100mV CH4 500mA M200µs A CH4 800mA 1 4 2 T 71 4 B W CH2 5V Ω VOUT LOAD STEP 500mA SW 10949 012 CH2 10V CH3 5V M1ms A CH1 1 32V 1 3 2 T 23 2 B W B W CH1 2V 10949 013 ENABLE CHANNEL 1 VOUT AND CHANNEL 2 SW SW SW ENABLE VOUT CH2 10V CH3 5V M1ms A CH1 1 52V 1 3 2 T 52 4 B W B W CH1 2V 10949 014 SW SW ENABLE VOUT CH...

Страница 8: ...UG 456 Evaluation Board User Guide Rev 0 Page 8 of 12 EVALUATION BOARD SCHEMATIC AND ARTWORK Figure 16 ADP2442 EVALZ Evaluation Board Schematic 10949 017 ...

Страница 9: ...2 Figure 17 ADP2442 EVALZ Evaluation Board Top Layer Figure 18 ADP2442 EVALZ Evaluation Board Third Layer Figure 19 ADP2442 EVALZ Evaluation Board Second Layer Figure 20 ADP2442 EVALZ Evaluation Board Bottom Layer 10949 018 10949 019 10949 020 10949 021 ...

Страница 10: ...LCC 270 pF 50 V 0603 X7R Determine by the user 1 R1 Resistor 49 9 Ω 1 10 W 1 0603 SMD Determined by user 2 R3 R8 Resistor 10 kΩ 1 10 W 1 0603 SMD Determined by user 1 R7 Resistor 50 kΩ 1 10 W 1 0603 SMD Determined by user 1 R2 Resistor 73 2 kΩ 1 10 W 1 0603 SMD Determined by user 1 R5 Resistor 118 kΩ 1 10 W 1 0603 SMD Determined by user 1 R6 Resistor 182 kΩ 1 10 W 11 0603 SMD Determined by user 1 ...

Страница 11: ...Evaluation Board User Guide UG 456 Rev 0 Page 11 of 12 NOTES ...

Страница 12: ...ny other party for any reason Upon discontinuation of use of the Evaluation Board or termination of this Agreement Customer agrees to promptly return the Evaluation Board to ADI ADDITIONAL RESTRICTIONS Customer may not disassemble decompile or reverse engineer chips on the Evaluation Board Customer shall inform ADI of any occurred damages or any modifications or alterations it makes to the Evaluat...

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