Analog Devices ADP1148 - Manuals

Page 2 - ELECTRICAL CHARACTERISTICS; IN

– 2 – REV. A ADP1148, ADP1148-3.3, ADP1148-5–SPECIFICATIONS ELECTRICAL CHARACTERISTICS Parameter Symbol Conditions 2 Min Typ Max Units FEEDBACK VOLTAGE ADP1148 Only V 10 V IN = 9 V 1.21 1.25 1.29 V FEEDBACK CURRENT ADP1148 Only I 10 0.2 1.0 µ A REGULATED OUTPUT VOLTAGE V OUT V IN = 9 V ADP1148-3.3 I...

Page 3 - ABSOLUTE MAXIMUM RATINGS; ORDERING GUIDE

– 3 – REV. A ADP1148, ADP1148-3.3, ADP1148-5 ELECTRICAL CHARACTERISTICS Parameter Symbol Conditions 2 Min Typ Max Units FEEDBACK VOLTAGE ADP1148 Only V 10 V IN = 9 V 1.20 1.25 1.30 V REGULATED OUTPUT VOLTAGE V OUT V IN = 9 V ADP1148-3.3 I LOAD = 700 mA 3.17 3.33 3.4 V ADP1148-5 I LOAD = 700 mA 4.85 ...

Page 4 - PIN FUNCTION DESCRIPTIONS; Mnemonic; PIN CONFIGURATIONS

ADP1148, ADP1148-3.3, ADP1148-5 – 4 – REV. A CAUTIONESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readilyaccumulate on the human body and test equipment and can discharge without detection. Althoughthe ADP1148, ADP1148-3.3, ADP1148-5 feature proprietary ESD ...

Page 7 - APPLICATIONS; Selection For Output Current; L and C; unless otherwise indicated.

ADP1148, ADP1148-3.3, ADP1148-5 – 7 – REV. A APPLICATIONS The ADP1148 uses a current-mode, constant off-time structureto switch a pair of external complementary N- and P-channelMOSFETs. The operating frequency of the device is deter-mined by the value of the external capacitor connected to theC T pi...

Page 8 - and C; Selection; All trademarks are the property of their respective holders.

ADP1148, ADP1148-3.3, ADP1148-5 – 8 – REV. A As the operating frequency is increased, the gate charge losseswill cause reduced efficiency (see Efficiency section). The fullformula for operating frequency is given by: f = ( 1 – V OUT /V IN )/t OFF where t OFF = 1.3 × 10 4 × C T × V REG /V OUT. V REG ...

Page 9 - Transient Response

ADP1148, ADP1148-3.3, ADP1148-5 – 9 – REV. A An additional 0.1 µ F – 1 µ F ceramic bypass capacitor is advised on V IN Pin 3 parallel with C IN . The selection of C OUT is driven by the required effective series resistance (ESR). The ESR ofC OUT must be less than twice the value of R SENSE for prope...

Page 10 - Figure 16. Output Crowbar Interface; Troubleshooting; Waveforms

ADP1148, ADP1148-3.3, ADP1148-5 – 1 0 – REV. A Design Example As a design example, assume V IN = 12 V (nominal), V OUT = 5 V, I MAX = 2 A, and f = 200 kHz, R SENSE . C T , and L can immedi- ately be calculated: R SENSE = 100 mV/2 = 50 m Ω t OFF = (1/200 kHz) × [1 – (5/12)] = 2.92 µ s C T = 2.92 µ s/...

Page 11 - Board Layout

ADP1148, ADP1148-3.3, ADP1148-5 – 1 1 – REV. A Board Layout When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the ADP1148.These items are also illustrated graphically in the layout diagramof Figure 18. Check the following in your layout: ...

Page 14 - OUTLINE DIMENSIONS

ADP1148, ADP1148-3.3, ADP1148-5 – 1 4 – REV. A OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 14-Lead Plastic DIP (N-14) 14 1 7 8 0.795 (20.19) 0.725 (18.42) 0.280 (7.11)0.240 (6.10) PIN 1 0.325 (8.25) 0.300 (7.62) 0.015 (0.381) 0.008 (0.204) 0.195 (4.95) 0.115 (2.93) SEATINGPLANE 0.022 (0....