MAX1677 Evaluation MAX1677 evaluation kit) fully assembled tested

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MAX1677 Evaluation MAX1677 evaluation kit) fully assembled tested

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MAX1677 Evaluation
MAX1677 evaluation kit) fully assembled tested surface-mount circuit board that contains separate switching-regulator circuits. first circuit configured +3.3V main output +20V bias voltage. accepts inputs from +0.7V +3.3V. main +3.3V output supplies 350mA from 2-cell input, 140mA from 1-cell input, while bias output supplies 12mA +20V. second circuit converts +0.7V +3.3V battery voltage +3.3V main output -20V bias voltage. main +3.3V output supplies 350mA from 2-cell input, 140mA from 1-cell input, while bias output supplies 10mA -20V. MAX1677 features internal N-channel MOSFET switches, synchronous rectifier, low-battery comparator, selectable PFM/PWM mode. MAX1677 provides quiescent current high efficiency- maximum battery life. Operation 300kHz allows tiny surface-mount inductors.
Features
+0.7V MAINOUT Battery Input Voltage Dual Output Voltages +3.3V Main Output +20V Bias Output +3.3V Main Output -20V Bias Output Outputs Also Adjustable with External Resistors 350mA from 2-Cell Input (Main Output 140mA from 1-Cell Input (Main Output) 12mA Output Current (LCD Bias Output) Internal N-Channel Switches Synchronous Rectifier Shutdown Current 300kHz Switching Frequency Surface-Mount Components Fully Assembled Tested
Evaluates: MAX1677
Ordering Information
PART MAX1677EVKIT TEMP. RANGE +70°C PACKAGE QSOP
Component List
DESIGNATION C10, C13, DESCRIPTION 100µF, low-ESR tantalum caps TPSD107M010R0100 Sprague 593D107X0010D2T 0.1µF ceramic capacitors 4.7µF, tantalum capacitors TPSC475M035R0600 Sprague 595D475X0035C2T 2.2µF, ceramic capacitor United Chemi-Con/Marcon THCR30E1E225Z 1µF, ceramic capacitors Taiyo Yuden EMK316BJ105KL C3216X7R1C105M installed 20V, 0.5A Schottky diodes Motorola MBR0520LT3 40V, 0.5A Schottky diodes Motorola MBR0540T3 DESIGNATION DESCRIPTION 10µH inductors Sumida CR54-100 10µH inductors Murata LQH4N100K04 NLC32522T-100K 1.5M resistor 100k resistors resistors 1.6M resistor installed MAX1677EEE 3-pin headers Shunts MAX1677 board MAX1677 data sheet
R6-R10, R14-R16 JU1-JU6
C16, C15,
None None None
Maxim Integrated Products
price, delivery, place orders, please contact Maxim Distribution 1-888-629-4642, visit Maxim's website www.maxim-ic.com.
MAX1677 Evaluation Evaluates: MAX1677
Component Suppliers
SUPPLIER Dale-Vishay Motorola Murata Sprague Sumida Taiyo Yuden United ChemiCon/Marcon PHONE 803-946-0690 402-564-3131 602-303-5454 814-237-1431 603-224-1961 708-956-0666 408-573-4150 847-390-4373 847-696-2000 803-626-3123 402-563-6418 602-994-6430 814-238-0490 603-224-1430 708-956-0702 408-573-4159 847-390-4428 847-696-9278
Detailed Description
MAX1677 contains separate switchingregulator circuits. first circuit provides +3.3V main output +20V bias output. second circuit provides +3.3V main output -20V bias output. Both circuits require +0.7V +3.3V input voltage range. main +3.3V output supplies 350mA from 2-cell input, 140mA from 1-cell input, while bias output supplies 12mA. main output voltage also adjusted from +2.5V +5.5V with external resistors. output also adjustable. main boost converter three operational modes: low-power mode, highpower mode, high-power mode with internal oscillator synchronized external clock.
Note: Please indicate that using MAX1677 when contacting these component suppliers.
Jumper Selection
Shutdown Mode MAX1677 features shutdown mode that reduces MAX1677 quiescent current less than (typ), preserving battery life. 3-pin headers, JU4, select shutdown mode each circuit. Table lists selectable jumper options. Controlling Using LCDON LCDON used turn bias voltage. Jumpers control LCDON pins +LCD -LCD output circuits, respectively. 3.3V outputs must also outputs operate. Table lists LCDON jumper options.
_Quick Start
MAX1677 fully assembled tested. Follow these steps verify board operation. turn power supply until connections completed.
+3.3V +LCD Output
Connect +1.1V +3.3V supply pad. Connect ground pad. Note: input voltage drop 0.7V after startup. Connect voltmeters VOUT +LCDOUT pads. Verify that shunts across pins JU1, JU2, JU3. Turn power supply verify that main output +3.3V bias output +20V.
Table Jumper JU1/JU4 Functions
SHUNT LOCATION Connected Connected VOUT VOUT OUTPUT Shutdown mode, VOUT VDIODE MAX1677 enabled, VOUT +3.3V
+3.3V -LCD Output
Connect +1.1V +3.3V supply pad. Connect ground pad. Note: input voltage drop 0.7V after start-up. Connect voltmeters VOUT -LCDOUT pads. Verify that shunts across pins JU4, JU5, JU6. Turn power supply verify that main output +3.3V -LCD Bias output -20V. instructions selecting feedback resistors other output voltages, refer Design Procedure section MAX1677 data sheet.
Table Jumper JU2/JU5 Functions
SHUNT LOCATION LCDON Connected Connected VOUT LCDOUT OUTPUT +LCDOUT VDIODE, -LCDOUT +LCDOUT +20V, -LCDOUT -20V
MAX1677 Evaluation
Operating Mode main boost converter three operational modes: low-power mode; high-power, low-noise mode; high-power mode with internal oscillator synchronized external clock. operates 300kHz switching frequency allows small inductor values. switching frequency also synchronized external clock ranging from 200kHz 400kHz. 3-pin headers select operating mode each circuit. Table lists jumper options.
Evaluating Other Output Voltages
main output +3.3V grounding feedback pins (FB) traces shorting R10. generate main output voltages other than +3.3V (+2.5V +5.5V), traces across select external voltage divider resistors (R1, R10). Refer Design Procedure section MAX1677 data sheet instructions selecting R10. ±20V bias output voltages with voltage dividers (R3, R11, R12) feedback pins (LCDFB). generate output voltages other than ±20V, refer Setting Output Voltage section MAX1677 data sheet.
Evaluates: MAX1677
Table Jumper JU3/JU6 Functions
SHUNT LOCATION CLK/SEL OPERATING MODE Low-power mode, MAX1677 operates mode. High-power, low-noise mode, MAX1677 operates mode. Synchronized highpower mode, CLK/SEL driven external clock between 200kHz 400kHz.
Changing Current Limit
inductor current limit 225mA 350mA. factory-configured 350mA. limit 225mA, trace shorting insert resistor. This allows smallest possible inductors low-current displays. Boost Converter section MAX1677 data sheet more information.
Connected
Connected VOUT
Open
CLK/SEL connected CLK/SEL
Evaluates: MAX1677
MAX1677 Evaluation
Figure MAX1677 Schematic (Positive LCD)
VOUT 10µH MBR0520L LCDPOL PGND 0.1µF OPEN VOUT OPEN CLK/SEL 10µH MBR0540 OPEN SHORT TRACE) 100µF VOUT +3.3V SHORT VOUT TRACE) VOUT POUT LCDON 100µF
LCDON
1.25V
0.1µF VOUT OPEN LCDLX
MAX1677
CLK/SEL
+LCDOUT +20V 4.7µF OPEN 1.5M
SHORT TRACE) LCDGND
LCDFB 100k
VOUT 10µH MBR0520L LCDPOL PGND 0.1µF OPEN VOUT OPEN CLK/SEL 10µH OPEN OPEN SHORT TRACE) 100µF VOUT +3.3V SHORT TRACE) VOUT POUT LCDON 100µF
Figure MAX1677 Schematic (Negative LCD)
LCDON
1.25V
0.1µF VOUT OPEN LCDLX SHORT TRACE) LCDGND 2.2µF
MAX1677
CLK/SEL
MBR0540 MBR0540 4.7µF
-LCDOUT -20V
OPEN
1.6M 100k
Evaluates: MAX1677
LCDFB
MAX1677 Evaluation
MAX1677 Evaluation Evaluates: MAX1677
1.0"
Figure MAX1677 Component Placement Guide-Component Side
MAX1677 Evaluation Evaluates: MAX1677
1.0"
Figure MAX1677 Board Layout-Component Side
MAX1677 Evaluation Evaluates: MAX1677
1.0"
Figure MAX1677 Board Layout-Solder Side
Maxim cannot assume responsibility circuitry other than circuitry entirely embodied Maxim product. circuit patent licenses implied. Maxim reserves right change circuitry specifications without notice time.
_Maxim Integrated Products, Gabriel Drive, Sunnyvale, 94086 408-737-7600 1999 Maxim Integrated Products Printed registered trademark Maxim Integrated Products.

MAX1677 Evaluation MAX1677 evaluation kit) fully assembled tested

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