ANALOG DEVICES LTM4702EY Step Down Module Regulator Low Noise Reference Instruction Manual
- June 16, 2024
- Analog Devices
Table of Contents
ANALOG DEVICES LTM4702EY Step Down Module Regulator Low Noise Reference
Instruction Manual
DESCRIPTION
Evaluation board EVAL-LTM4702-AZ is a step-down DC/DC switching converter featuring the LTM®4702 μModule® regulator. The evaluation board is designed to deliver 8A maximum output current from a 4V to 16V input. The LTM4702 employs Silent Switcher® architecture with internal hot loop bypass capacitors to achieve both low EMI and high efficiency. The LTM4702 contains a current mode regulator IC, power inductor, and a modest amount of input and output capacitance. A single resistor (R3) sets the output voltage, providing unity gain operation over the output range, resulting in virtually constant output noise independent of output voltage.
The EVAL-LTM4702-AZ evaluation board default switching frequency is 800kHz. An external resistor is placed from RT pin to GND (R7) to set the switching frequency.
SYNC pin programs three different operating modes (JP1 jumper): select PULSE for pulse-skipping mode with improved efficiency at light loads; select FCM for forced continuous mode operation where fixed frequency operation is more critical than low current efficiency and where the lowest output ripple is desired; select SYNC to synchronize to an external clock signal.
The RUN terminal can be used to set the LTM4702 in shutdown mode. The power good output (PG) will be low when the output voltage is outside of the ±7.5% regulation window. When the power good feature is used, set the PGSET resistor (R1) value according to the regulator output voltage.
The LTM4702 data sheet gives a complete description of the operation and
application information. The data sheet must be read in conjunction with this
evaluation board.
Design files for this circuit board are available.
BOARD PHOTO
Part marking is either ink mark or laser mark
PERFORMANCE SUMMARY
Specifications are at TA = 25°C
| PARAMETER | CONDITIONS | MIN TYP MAX | V |
|---|---|---|---|
| Input Voltage Range | 4 16 | V | |
| Output Voltage | VIN = 4V to 16V, IOUT = 0A to 8A | 1 ±2% | A |
| Maximum Output Current | VIN = 4V to 16V | 8 | A |
| Typical Switching Frequency | 800 | kHz | |
| Typical Efficiency | VIN = 12V, IOUT = 8A | 80.5 | % |
QUICK START PROCEDURE
Evaluation board EVAL-LTM4702-AZ is easy to set up to evaluate the performance of the LTM4702. See Figure 1 for the proper measurement equipment setup and follow the procedure below.
-
With power off, connect the input power supply to VIN (4V to 16V) and GND (input return).
-
Connect the 1V output load between VOUT and GND (Initial load: no load).
-
Connect the DVMs to the input and output. Set default jumper position:
JP1: FCM ON
JP2: 120 PS ON -
Turn on the input power supply and check for the proper output voltage. VOUT should be 1V ±2%.
-
Once the proper output voltage is established, adjust the load within the operating range and observe the output voltage regulation, efficiency, and other parameters.
NOTE: When measuring the output or input voltage ripple, do not use the long ground lead on the oscilloscope probe. See Figure 2 for the proper scope probe technique. Short, stiff leads may be soldered to the (+) and (–) terminals of an output capacitor. The probe’s ground ring needs to touch the (–) lead, and the probe tip needs to touch the (+) lead.
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 1. Proper Measurement Equipment Setup
Figure 2. Measuring Output Ripple Voltage
TEST RESULTS
Figure 3. Efficiency vs Load Current, VIN = 12V
Figure 4. Output Voltage Ripple (12VIN, 1V, 8A Output)
Figure 5. Load Step Transient Test (VIN = 12V, VOUT = 1V)
Figure 6. Thermal Image, VIN = 12V, 1V, 8A Output (No Heat Sink, No
Forced Airflow)
PARTS LIST
ITEM| QTY| REFERENCE| PART DESCRIPTION|
MANUFACTURER/PART NUMBER
---|---|---|---|---
1| 1| C1| CAP., ALUM POLY HYBRID, 100μF, 25V, 20%, 6.3mm × 7.7mm, AEC-Q200|
PANASONIC, EEHZC1E101XP
2| 1| C10| CAP. CER, 1μF, 25V, 10%, X7R, 0603, AEC-Q200| TDK,
CGA3E1X7R1E105K080AC
3| 2| C11, C12| CAP. CER, 22μF, 25V, 10%, X7R, 1210| MURATA,
GRM32ER71E226KE15L
4| 4| C13, C14, C15, C16| CAP. CER, 10μF, 6.3V, 20%, X7S, 0603| TDK,
C1608X7S0J106M080AC
5| 2| C6, C17| CAP. CER, 100μF, 10V, 20%, X5R, 1206, LOW ESR| TDK,
C3216X5R1A107M160AC
6| 3| C18, C23, C24| CAP. CER, 0.1μF, 25V, 10%, X7R, 0603| SAMSUNG,
CL10B104KA8NNNC
7| 1| C19| CAP. CER, 2200pF, 16V, 10%, X7R, 0603| VISHAY, VJ0603Y222KXJCW1BC
8| 1| C2| CAP. CER, 22μF, 25V, 20%, X5R, 0805, AEC-Q200| MURATA,
GRT21BR61E226ME13L
9| 2| C21, C22| CAP FEEDTHRU, 4.7μF, 10V, 20%, 0805, 3-TERMINAL| MURATA,
NFM21PC475B1A3D
10| 3| C3, C4, C5| CAP. CER, 2.2μF, 25V, 10%, X5R, 0603|
MURATAGRM188R61E225KA12D
11| 1| C9| CAP. CER, 1μF, 10V, 10%, X7R, 0805| AVX, 0805ZC105KAT2A
12| 1| FB1| IND., CHIP FERRITE BEAD, 0.015Ω, DCR, 5.1A| WURTH ELEKTRONIK,
74279228600
13| 1| L1| IND., POWER SHIELDED WIREWOUND, 0.0073Ω, DCR, 9.5A| WURTH
ELEKTRONIK, 744373240022
14| 1| R1| RES., SMD, 49.9k, 1%, 1/10W, 0603, AEC-Q200| PANASONIC, ERJ-
3EKF4992V
15| 1| R10| RES., SMD, 0Ω, 1%, 1/4W, 1206| VISHAYWSL, 120600000ZEA9
16| 1| R12| RES., 1.2k, 1%, 1/10W, 0603, AEC-Q200| VISHAY, CRCW06031K20FKEA
17| 1| R13| RES., SMD, 0Ω, JUMPER, 1/10W, 0603, AEC-Q200,PRECISION POWER|
VISHAY, CRCW06030000Z0EA
18| 2| R2, R5| RES., SMD, 100k, 1%, 1/10W, 0603, AEC-Q200| PANASONIC, ERJ-
3EKF1003V
19| 1| R3| RES., SMD, 10k 1%, 1/10W, 0603, AEC-Q200| PANASONIC, ERJ-3EKF1002V
20| 1| R4| RES., SMD, 1Ω, 1%, 1/10W, 0603| YAGEO, RC0603FR-071RL
21| 1| R7| RES., 137k, 1%, 1/10W, 0603, AEC-Q200| VISHAY, CRCW0603137KFKEA
22| 1| U1| IC-ADI, 18VIN, 8A, Silent Switcher, μModule REGULATOR| ANALOG
DEVICES, LTM4702EY#PBF
18| 0| C7, C8, C20, C25| OPTIONAL CAPACITOR|
19| 0| R6, R8, R9, R11| OPTIONAL RESISTOR|
20| 0| L2| OPTIONAL INDUCTOR|
24| 2| J1, J2| CONN., PCB, SMA, FEMALE JACK, RCP, 50Ω| MOLEX, 732511350
26| 2| JP1, JP2| CONN., HDR, MALE, 2 × 3, 2mm, VERT, ST, THT| WURTH
ELEKTRONIK, 62000621121
27| 4| | STANDOFF, BRD, SPT, SNAP-FIT, 9.53mm LENGTH, EVAL BOARD MTG|
KEYSTONE, 8832
28| 2| | CONN., SHUNT, FEMALE, 2-POS, 2mm| KEYSTONE, 8831
29| 1| PCBs| FAB PRINTED CIRCUIT BOARD| WURTH ELEKTRONIK, 702931000
SCHEMATIC DIAGRAM
REVISION HISTORY
| REV | DATE | DESCRIPTION | PAGE NUMBER |
|---|---|---|---|
| 0 | 04/23 | Initial Release | — |
ESD Caution
ESD (electrostatic discharge) sensitive device. Charged devices and
circuit boards can discharge without detection. Although this product features
patented or proprietary protection circuitry, damage may occur on devices
subjected to high energy ESD. Therefore, proper ESD precautions should be
taken to avoid performance degradation or loss of functionality
Legal Terms and Conditions
By using the evaluation board discussed herein (together with any tools,
components documentation or support materials, the “Evaluation Board”), you
are agreeing to be bound by the terms and conditions set forth below
(“Agreement”) unless you have purchased the Evaluation Board, in which case
the Analog Devices Standard Terms and Conditions of Sale shall govern. Do not
use the Evaluation Board until you have read and agreed to the Agreement. Your
use of the Evaluation Board shall signify your acceptance of the Agreement.
This Agreement is made by and between you (“Customer”) and Analog Devices,
Inc. (“ADI”), with its principal place of business at One Technology Way,
Norwood, MA 02062, USA. Subject to the terms and conditions of the Agreement,
ADI hereby grants to Customer a free, limited, personal, temporary, non-
exclusive, non-sublicensable, non-transferable license to use the Evaluation
Board FOR EVALUATION PURPOSES ONLY. Customer understands and agrees that the
Evaluation Board is provided for the sole and exclusive purpose referenced
above, and agrees not to use the Evaluation Board for any other purpose.
Furthermore, the license granted is expressly made subject to the following
additional limitations: Customer shall not (i) rent, lease, display, sell,
transfer, assign, sublicense, or distribute the Evaluation Board; and (ii)
permit any Third Party to access the Evaluation Board. As used herein, the
term “Third Party” includes any entity other than ADI,Customer, their
employees, affiliates and in-house consultants. The Evaluation Board is NOT
sold to Customer; all rights not expressly granted herein, including ownership
of the Evaluation Board, are reserved by ADI. CONFIDENTIALITY. This Agreement
and the Evaluation Board shall all be considered the confidential and
proprietary information of ADI. Customer may not disclose or transfer any
portion of the Evaluation Board to any 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
Evaluation Board, including but not limited to soldering or any other activity
that affects the material content of the Evaluation Board. Modifications to
the Evaluation Board must comply with applicable law, including but not
limited to the RoHS Directive. TERMINATION. ADI may terminate this Agreement
at any time upon giving written notice to Customer. Customer agrees to return
to ADI the Evaluation Board at that time.
LIMITATION OF LIABILITY. THE EVALUATION BOARD PROVIDED HEREUNDER IS
PROVIDED “AS IS” AND ADI MAKES NO WARRANTIES OR REPRESENTATIONS OF ANY KIND
WITH RESPECT TO IT. ADI SPECIFICALLY DISCLAIMS ANY REPRESENTATIONS,
ENDORSEMENTS, GUARANTEES, OR WARRANTIES, EXPRESS OR IMPLIED, RELATED TO THE
EVALUATION BOARD INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF
MERCHANTABILITY, TITLE, FITNESS FOR A PARTICULAR PURPOSE OR NONINFRINGEMENT OF
INTELLECTUAL PROPERTY RIGHTS. IN NO EVENT WILL ADI AND ITS LICENSORS BE LIABLE
FOR ANY INCIDENTAL, SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES RESULTING FROM
CUSTOMER’S POSSESSION OR USE OF THE EVALUATION BOARD, INCLUDING BUT NOT
LIMITED TO LOST PROFITS, DELAY COSTS, LABOR COSTS OR LOSS OF GOODWILL. ADI’S
TOTAL LIABILITY FROM ANY AND ALL CAUSES SHALL BE LIMITED TO THE AMOUNT OF ONE
HUNDRED US DOLLARS ($100.00). EXPORT. Customer agrees that it will not
directly or indirectly export the Evaluation Board to another country, and
that it will comply with all applicable United States federal laws and
regulations relating to exports. GOVERNING LAW. This Agreement shall be
governed by and construed in accordance with the substantive laws of the
Commonwealth of Massachusetts (excluding conflict of law rules). Any legal
action regarding this Agreement will be heard in the state or federal courts
having jurisdiction in Suffolk County, Massachusetts, and Customer hereby
submits to the personal jurisdiction and venue of such courts. The United
Nations Convention on Contracts for the International Sale of Goods shall not
apply to this Agreement and is expressly disclaimed.
www.analog.com
ANALOG DEVICES, INC. 2023
Downloaded from Arrow.com.
