 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| 19-1400; Rev 0; 11/98 MAX1692 Evaluation Kit General Description The MAX1692 evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board that contains a pulse-width-modulated (PWM), step-down DC-DC converter. The EV kit provides a +2.5V output voltage from a +2.7V to +5.5V input source. It delivers up to 600mA output current. The MAX1692 features internal MOSFET switches, low dropout voltage, and a 1.2%-accurate 1.25V reference. The MAX1692 EV kit provides low quiescent current and high efficiency (up to 95%) for maximum battery life. Operation at 750kHz allows the use of a tiny surface-mount inductor. o +2.7V to +5.5V Input Voltage Range o +2.5V Output Voltage or Adjustable Output from 1.25V to VIN o 600mA Output Current o 100% Duty Cycle in Dropout o 750kHz Fixed-Frequency PWM Operation o Internal MOSFET Switch and Synchronous Rectifier o 0.1A IC Shutdown Current o Surface-Mount Components o Fully Assembled and Tested Features Evaluates: MAX1692 Component List DESIGNATION QTY C1 1 DESCRIPTION 10F, 6.3V, X5R ceramic capacitor Taiyo Yuden JMK325BJ106MN 47F, 6.3V, low ESR, electrolytic capacitor, Sanyo 6TPA47M or 47F, 16V tantalum capacitor Sprague 594D476X0016C2T 0.1F ceramic capacitor 0.22F ceramic capacitor 47pF ceramic capacitor 10H inductor Sumida CDR63B-100 (shielded) or CD43-100 (unshielded) 309k, 1% resistor 301k, 1% resistor 100k, 5% resistor MAX1692EUB 3-pin header Shunt (JU1) 2-pin header MAX1692 PC Board MAX1692 data sheet Ordering Information PART MAX1692EVKIT TEMP. RANGE 0C to +70C IC-PACKAGE 10 MAX C2 1 C3 C4 C5 L1 R1 R2 R3 U1 JU1 None JU2 None None 1 1 1 1 1 1 1 1 1 1 1 1 1 Quick Start The MAX1692 EV kit is fully assembled and tested. Follow these steps to verify board operation. Do not turn on the power supply until all connections are completed. 1) Connect a +2.7V to +5.5V supply to the VIN pad. Connect the ground to the GND pad. 2) Connect a voltmeter to the VOUT pad. 3) Verify that the shunt is across JU1 pins 1 and 2. 4) Turn on the power supply and verify that the output is at +2.5V. Detailed Description Jumper Selection Shutdown Mode The MAX1692 EV kit features a shutdown mode that reduces the MAX1692 IC's quiescent current to 0.1A, preserving battery life. The 3-pin header, JU1, selects the shutdown mode (Table 1). Component Suppliers SUPPLIER Dale-Vishay Sanyo Sprague Sumida Taiyo Yuden PHONE 402-564-3131 619-661-6835 603-224-1961 708-956-0666 408-573-4150 FAX 402-563-6418 619-661-1055 603-224-1430 708-956-0702 408-573-4159 Table 1. Jumper JU1 Functions SHUNT LOCATION 1&2 2&3 SHDN PIN Connected to VIN MAX1692 OUTPUT MAX1692 enabled, VOUT = 2.5 Note: Please indicate that you are using the MAX1692 when contacting these component suppliers. Connected to GND Shutdown mode, VOUT = 0 1 ________________________________________________________________ Maxim Integrated Products For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. MAX1692 Evaluation Kit Evaluates: MAX1692 Table 2. Jumper JU2 Functions SHUNT LOCATION On SYNC/PWM PIN Connected to VIN Pulled to GND via 100k Off (not installed) Driven from external clock OPERATING MODE MAX1692 operates in PWM low-noise mode. MAX1692 operates in PWM/PFM mode. SYNC/PWM pin is driven by an external clock between 500kHz and 1000kHz. Table 3. R1/R2 for Other Output Voltages VOUT (V) 1.50 1.80 2.50 2.70 3.32 R1 (1%) 66.5k 140k 309k 357k 511k R2 (1%) 301k 301k 301k 301k 301k Changing Current Limit The inductor current limit can be set to 0.6A or 1.2A. The EV kit is factory-configured for a 1.2A limit. To set the limit to 0.6A, cut the PC trace shorting JU3 pins 1 & 2, and then short JU3 pins 2 & 3. This allows for use of the smallest possible inductor for low-current applications. Operating Mode The MAX1692 operates in one of three modes to optimize performance. A fixed-frequency (PWM) mode switches at a fixed frequency for easy post-filtering. A synchronizable PWM mode uses an external clock to control harmonics. A PWM/PFM mode extends battery life by operating in PWM mode under heavy loads and in PFM mode under light loads for reduced power consumption. The EV kit operates at a 750kHz switching frequency and allows the use of a small-value inductor. The switching frequency can also be synchronized to an external clock ranging from 500kHz to 1000kHz. The 2pin header JU2 selects the operating mode (Table 2). Evaluating Other Output Voltages The EV kit's output is set to +2.50V by connecting FB to resistor-divider R1/R2. However, the output voltage can also be adjusted between +1.232V and VIN by changing R1 and R2 values. Select feedback resistor R2 in the 5k to 500k range. R1 is then given by: R1 = R2 [(VOUT / VFB) - 1] where VFB = 1.232V and VOUT = output voltage. The unloaded output voltage is typically 1% above the nominal output voltage. Table 3 lists values for R1 for different output voltages. VIN 2.7V TO 5.5V 1 C1 10F 6.3V 2 C3 0.1F IN LX 9 L1 10H 10 C2 47F 6.3V R1 309k 1% VIN 1 R2 301k 1% JU3 3 C5 47pF VOUT 2.5V BP U1 MAX1692 PGND SHDN JU1 1 3 2 8 SHDN FB 5 4 VIN JU2 SYNC/PWM R3 100k C4 0.22F 7 REF LIM SYNC/PWM GND 6 3 2 Figure 1. MAX1692 EV Kit Schematic 2 _______________________________________________________________________________________ MAX1692 Evaluation Kit Evaluates: MAX1692 1.0" Figure 2. MAX1692 EV Kit Component Placement Guide-- Component Side 1.0" Figure 3. MAX1692 EV Kit PC Board Layout--Component Side 1.0" Figure 4. MAX1692 EV Kit PC Board Layout--Solder Side _______________________________________________________________________________________ 3 MAX1692 Evaluation Kit Evaluates: MAX1692 NOTES 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. 4 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 1998 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. |
Price & Availability of MAX1692EVKIT
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |