View MAX5003EVKIT_990450.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

19-1914; Rev 1; 1/01
MAX5003 Evaluation Kit
General Description
The MAX5003 evaluation kit (EV kit) provides a regulated 5V output voltage up to 1A while operating from a +36V to +72V input voltage. The MAX5003 EV kit is a fully assembled and tested surface-mount printed circuit (PC) board. It comes with the output voltage set to 5V. This EV kit is configured as a flyback converter, and can easily be configured for either isolated or nonisolated operation by selecting the state of a mechanical switch. Additionally, for systems in which the input and output ground references are not at the same potential and for which isolation is not desired, the user has the option to install a level-shifter (not supplied) in the controller feedback loop. WARNING: Dangerous voltages are present on this EV kit and on equipment connected to it. Users who power up this EV kit or power the sources connected to it must be careful to follow safety procedures appropriate to working with high-voltage electrical equipment. Under severe fault or failure conditions, this EV kit may dissipate large amounts of power, which could result in the mechanical ejection of a component or of component debris at high velocity. Operate this kit with care to avoid possible personal injury. o 5V at 1A Output o +36V to +72V Input Voltage Range o 300kHz Switching Frequency o Can be Configured for -48V Input and +5V Output o Selectable Isolated or Nonisolated Operation o Proven PC Board Layout o Fully Assembled and Tested Surface-Mount Board
Features
Evaluates: MAX5003
Ordering Information
PART MAX5003EVKIT *With air flow. TEMP. RANGE 0C to +70C* IC PACKAGE 16 QSOP
Component List
DESIGNATION QTY DESIGNATION C1 C2, C3 C5 C6 C7 C8 C9 C10 C11, C13, C17 C12 C16 D1 D2 N1 Q1 1 2 1 1 1 1 1 1 3 1 1 1 1 1 0 DESCRIPTION 33F, 100V electrolytic capacitor Sanyo 100MV33CZ 22F, 10V ceramic capacitors Taiyo Yuden LMK432BJ226MM 2200pF 10% ceramic capacitor 3900pF 10% ceramic capacitor 0.01F ceramic capacitor 10F, 16V ceramic capacitor Taiyo Yuden EMK325BJ106MN 100pF 10% ceramic capacitor 0.47F ceramic capacitor 0.1F ceramic capacitors 390pF 10% ceramic capacitor 4.7F, 25V tantalum capacitor AVX TAJB475M025 30V, 1A Schottky diode Fairchild MBRS130L Small-signal switching diode Central Semiconductor CMSD4448 200V, 5.2A N-channel MOSFET International Rectifier IRF620S Not installed 1 DESIGNATION QTY Q2 R1 R2 R3 R4, R22, R23 R5 R6 R7 R8, R15 R9 R10 R11 R12 R13 R14 R16, R17 R18 1 1 1 1 3 1 1 1 2 1 1 1 1 1 1 2 0 DESCRIPTION 2N3904-type NPN transistor Central Semiconductor CMPT3904 or equivalent 41.2k 1% resistor 17.4k 1% resistor 68k 5% resistor 1M 5% resistors 39k 5% resistor 51k 5% resistor 200k 5% resistor 43 5% resistors 0.11 1%, 1/4W resistor Dale WSL-1206/0.11/1% 100 5% resistor 100k 5% resistor 20k 5% resistor 1.3k 5% resistor 240k 5% resistor 24.9k 1% resistors Not installed
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
MAX5003 Evaluation Kit Evaluates: MAX5003
Component List (continued)
DESIGNATION QTY R19 R20 R21 SW1 SW2 T1 U1 U2 U3 None None None 0 1 1 1 1 1 1 1 1 1 1 1 DESCRIPTION Not installed 680 5% resistor 15 5% resistor DPDT switch SPDT switch 65H, 8:1:2.5 transformer Coiltronics CTX03-14502 MAX5003EEE (16-pin QSOP) 2.5V voltage reference Motorola TL431BCD Low-current optocoupler QT Opto MOC217 MAX5003 PC board MAX5003 data sheet MAX5003 EV kit data sheet
Table 1. Switch/Jumper Functions
FUNCTION Nonisolated, Non-level-shifted Feedback Mode (e.g., +48V input and +5V output) SWITCH/ JUMPER SW1 SW2 JU1 SW1 SW2 JU1 SW1 SW2 JU1 POSITION NON DIR Closed* (default trace) NON LVL Open (Cut) ISO LVL Open (Cut)
Nonisolated, Level-Shifted Feedback Mode (e.g., -48V input and +5V output)
Isolated Feedback Mode (input and output supplies isolated from one another) *Default setting
Component Suppliers
SUPPLIER AVX Central Semiconductor Coiltronics Dale-Vishay Fairchild International Rectifier Motorola QT Optoelectronics Sanyo Taiyo Yuden PHONE 803-946-0690 516-435-1110 561-241-7876 402-564-3131 408-822-2000 310-322-3331 303-675-2140 408-720-1440 619-661-6835 408-573-4150 FAX 803-626-3123 516-435-1824 561-241-9339 402-563-6418 408-822-2102 310-322-3332 303-675-2150 408-720-0848 619-661-1055 408-573-4159
3) Verify that switch SW1 is set to the NON position and SW2 is set to the DIR position. See Table 1 for a description of the switch settings. 4) Turn on the power and verify that the output voltage is +5V. 5) Refer to the Isolated Feedback section to modify the board for isolated operation. Refer to the Nonisolated Level-Shifted Feedback section to modify the board for operation with the input and output negative supplies at different potentials.
Detailed Description
Feedback Mode Selection
Switch SW1 selects the feedback configuration (isolated or nonisolated). If SW1 is set to the NON position, switch SW2 selects either direct feedback (for the case in which the input and output share the same ground) or level-shifted feedback. Switch SW2 is only effective when nonisolated feedback is selected. Jumper JU1 determines whether the input and output ground references are connected. Table 1 summarizes switch and jumper functions. Do not operate switches SW1 and SW2 when power is applied to the EV kit because the controller can be damaged.
Note: Please indicate that you are using the MAX5003 when contacting the above component suppliers.
Quick Start
The MAX5003 EV kit is fully assembled and tested. Follow these steps to verify board operation in nonisolated mode. Do not turn on the power supply until all connections are completed. 1) Connect a +36V to +72V power supply to the pad labeled VIN. Do not exceed 100V input voltage. The ground connects to the GND pad (-48V). 2) Connect a voltmeter and load (if any) to the +5V pad.
2
Isolated Feedback
To configure the MAX5003 EV kit for isolated operation, turn off the power supply and cut the JU1 PC board trace. Set the SW1 switch to the ISO position, and set the SW2 switch to the LVL position (setting SW2 to the
_______________________________________________________________________________________
MAX5003 Evaluation Kit
LVL position disconnects the R1-R2 resistor-divider from the MAX5003's FB pin, as required for isolated operation). Turn the power supply back on and verify that the output voltage is still +5V. Note that for the isolated configuration, the output ground and the input ground may differ by as much as 500V. Do not operate switches SW1 and SW2 when power is applied to the EV kit because the controller can be damaged. high signal to turn on transistor Q2. For normal operation, the SHDN pad can be connected to ground or left unconnected. Note that the logic-high signal used to drive the SHDN pad is referenced to the negative side of the input supply. For more details regarding undervoltage lockout, refer to the MAX5003 data sheet.
Evaluates: MAX5003
Current Limiting
The MAX5003 EV kit has a current-limiting feature implemented by current-sense resistor R9. The MAX5003 turns off switching FET N1 when the voltage at the CS pin reaches 100mV. Since R9 is a 0.11 resistor, this limits the current in the transformer primary to 0.91A peak, which corresponds to a typical output short-circuit current of 4.5A. R10, a 100 resistor, is connected between the current-sense resistor and the CS pin to enable current-sense blanking after N1 is turned on, as described in the MAX5003 data sheet.
Nonisolated Level-Shifted Feedback
To configure the MAX5003 EV kit for operation in a system in which the negative terminal of the input power supply is at a more negative potential than the negative terminal of the output power supply (for example, in a -48V input to +5V output application), first turn off the power supply and cut the JU1 PC board trace. Set the SW1 switch to the NON position, and set the SW2 switch to the LVL position. Locate parts R18, R19, and Q1 (directly above jumper JU1 on the PC board). Solder the following parts into the R18, R19, and Q1 locations: R18 = 36.5k 1% resistor (1206), R19 = 12.4k 1% resistor (1206), and Q1 = 60V 2N2907type PNP transistor (SOT23). Note that the initial DC output voltage accuracy and the temperature variation will be degraded in this configuration. Do not operate switches SW1 and SW2 when power is applied to the EV kit because the controller can be damaged.
Layout Considerations
The MAX5003 EV kit layout is optimized for fast switching and high currents. The input and output power and ground traces must both be as short and wide as possible to minimize unwanted parasitic inductance. This board was not designed per UL spacing specifications.
Undervoltage Lockout and Shutdown
The MAX5003 EV kit is configured to go into undervoltage lockout when VIN drops below 32V. The MAX5003 does not have a shutdown pin, but the undervoltage lockout state is equivalent to a shutdown state. The MAX5003 EV kit contains a shutdown function consisting of an NPN switching transistor (Q2) that can pull the VINDIV pin to ground. To place the MAX5003 in undervoltage lockout, drive the SHDN pad with a +5V logic-
_______________________________________________________________________________________
3
Evaluates: MAX5003
MAX5003 Evaluation Kit
Figure 1. MAX5003 EV Kit Schematic
1 D2 3 VDD C16 4.7F 25V 7 VDD 8 VDD VDD 2 5 D1 3 15 C8 10F 16V C5 2200pF 2 4 FREQ NDRV 1 N1 3 R19 OPEN 3 1 R18 OPEN SW2 R2 17.4k 1% JU1 CUT HERE 2 R20 680 R15 43 R14 240k REF 7 CON AGND REF COMP FB 9 R6 51k MAXTON R22 1M 1 8 R7 200k C12 390pF U2 TL431 2, 3 6, 7 NON 2 6 ISO 8 COMP 10 11 R13 1.3k 6 5 U3 MOC217 7 1 2 R3 68k 14 Q1 R8 43 3 SW1-A NON 1 ISO 5 C2 22F 10V C3 22F 10V ES C13 0.1F VCC +5V C17 0.1F 16 11 12 T1 9 10 R21 15 2 C1 33F 100V 1 VINDIV V+ R4 1M 2 3 C9 100pF R5 39k 2
4
U1 MAX5003
5 SS R10 100 PGND 13 NOT INSTALLED C10 0.47F R9 0.11 1/4W 1% R1 41.2k 1% GND LVL DIR 6 C11 0.1F REF CS 12 C7 0.01F R16 24.9k 1% C6 3900pF R17 24.9k 1%
GND (-48V)
VIN
Q2
SHDN
1
R11 100k
R12 20k
REF
REF
R23 1M
4
_______________________________________________________________________________________
SW1-B
MAX5003 Evaluation Kit Evaluates: MAX5003
1.0"
Figure 2. MAX5003 EV Kit Component Placement Guide-- Component Side
1.0"
1.0"
Figure 3. MAX5003 EV Kit PC Board Layout--Component Side
Figure 4. MAX5003 EV Kit PC Board Layout--Solder Side
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 5 (c) 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

▲Up To Search▲

Price & Availability of MAX5003EVKIT

	To Download MAX5003EVKIT Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .