Rainbow-electronics MAX749 Uživatelský manuál

Digitally Adjustable LCD Bias Supply_______________General DescriptionThe MAX749 generates negative LCD-bias contrastvoltages from 2V to 6V inputs. Fu

The Sumida CD54-470N (47µH, 720mA, 370mΩ) is suit-able for a wide range of applications, and the largerCD105-470N (47µH, 1.17A, 170mΩ) permits higher

CapacitorsOutput Filter CapacitorA 22µF, 30V surface-mount (SMT) tantalum output filtercapacitor typically maintains 100mVp-p output ripplewhen genera

MAX749Digitally Adjustable LCD Bias SupplyDIMAA1A2A3BB1CD1EE1eeAeBLMIN–0.0150.1250.0550.0160.0450.0080.0050.3000.2400.1000.

TA= TMINto TMAXMIN MAX125 300MAX749Digitally Adjustable LCD Bias Supply 2 ____________________________________________________________________________

MAX749Digitally Adjustable LCD Bias Supply_______________________________________________________________________________________ 38565-24 -20 -12 -4E

MAX749Digitally Adjustable LCD Bias Supply 4 ______________________________________________________________________________________PIN NAME FUNCTION1

_______________Detailed DescriptionThe MAX749 is a negative-output inverting power con-troller that can drive an external PNP transistor or P-channel

MAX749Once turned off, a one-shot holds the switch off for aminimum of 1µs, and the switch either stays off (if theoutput is in regulation), or turns

Figure 4. Count-Up OperationFigure 5. Reset Sequence without Shutdown. The device is notshut down during reset.Figure 6. Reset Sequence with ShutdownI

MAX749counter rolls over and sets the DAC to -VOUT(MIN),where -VOUT(MIN)= RFBx 6.66µA. In other words, a sin-gle rising edge of ADJ increments the DAC

Figure 9b. Maximum Output Current vs. Input Voltage, VOUT = -12VFigure 9c. Maximum Output Current vs. Input Voltage, VOUT = -15VFigure 9d. Maximum Out