ADP1621ARMZ-R7 Analog Devices Inc, ADP1621ARMZ-R7 Datasheet
ADP1621ARMZ-R7
Specifications of ADP1621ARMZ-R7
ADP1621ARMZ-R7TR
Related parts for ADP1621ARMZ-R7
ADP1621ARMZ-R7 Summary of contents
Page 1
FEATURES 92% efficiency (no sense resistor required) ±1.0% initial accuracy IC supply voltage range: 2 5.5 V Power-input voltage as low as 1.0 V Capable of high supply input voltage (>5.5 V) with an external NPN or a ...
Page 2
ADP1621 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 General Description ......................................................................... 1 Typical Application Circuit ............................................................. 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Absolute Maximum Ratings............................................................ 5 Thermal Resistance ...................................................................... 5 ESD Caution.................................................................................. 5 Simplified Block Diagram ............................................................... 6 ...
Page 3
SPECIFICATIONS 100 kΩ 200 kHz FREQ OSC Table 1. Parameter MAIN CONTROL LOOP Internal Soft Start Time 1 PIN Supply Voltage IN Supply Voltage 1 Shunt Regulation Voltage Shunt Resistance ...
Page 4
ADP1621 Parameter GATE DRIVER 9 GATE Rise Time 9 GATE Fall Time 1 The maximum input voltage is the shunt regulation voltage, which is typically 5.5 V and can range from 5 6.0 V over the specified temperature ...
Page 5
ABSOLUTE MAXIMUM RATINGS Table 2. Parameter IN to GND FB, COMP, SDSN, FREQ, GATE to GND CS to GND PIN to PGND Supply Current into IN Supply Current into PIN Storage Temperature Range 1 Junction Operating Temperature Range Junction Storage ...
Page 6
ADP1621 SIMPLIFIED BLOCK DIAGRAM FB COMP FREQ CS PGND GND V REF SOFT START 1.215V ERROR (2048 CYCLES) AMPLIFIER OSC 1.4V SET OSC SLOPE COMP PWM COMPARATOR + + UVLO n Figure 3. ADP1621 Simplified Block Diagram ...
Page 7
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Table 4. Pin Function Descriptions Pin No. Mnemonic Description 1 SDSN Shutdown and Synchronization Input. Turn the ADP1621 on by driving SDSN high; turn it off by driving SDSN low. If SDSN is left floating ...
Page 8
ADP1621 TYPICAL PERFORMANCE CHARACTERISTICS 100 0.01 0.1 LOAD CURRENT (A) Figure 5. Efficiency vs. Load Current T = 25° 3. OUT LOAD = ...
Page 9
MOSFET Q = 25nC MOSFET Q = 15nC G 10 MOSFET Q = 7nC 200 400 600 800 1000 1200 1400 SWITCHING FREQUENCY (kHz) Figure 11. PIN Supply ...
Page 10
ADP1621 250 30V 200 150 100 50 0 – LEAKAGE (nA) Figure 17. Temperature vs. CS Leakage 1.2113V AT 25° BIAS CURRENT IS MEASURED BY FORCING ...
Page 11
T = 25°C LOAD = 0. 3.3V CCM OPERATION OUT 4 CH4 = INDUCTOR CURRENT 2 CH2 = DRAIN VOLTAGE 1 CH1 5V CH2 5V M2µs CH4 500mAΩ Figure 23. CCM Switching Waveform ...
Page 12
ADP1621 THEORY OF OPERATION The ADP1621 is a fixed-frequency, current-mode, step-up dc/dc converter controller. It drives an external n-channel MOSFET to step the input voltage higher output voltage. It can be used for SEPIC, flyback, boost, buck-boost, ...
Page 13
CURRENT LIMIT The current limit is achieved by the COMP voltage clamp, owing to the current-mode operation of the ADP1621. A detailed explanation of how the current limit is determined can be found in the Current Limit section of the ...
Page 14
ADP1621 APPLICATION INFORMATION: BOOST CONVERTER In this section, an analysis of a boost converter is presented, along with guidelines for component selection. A typical boost- converter application circuit is shown in Figure 1. DUTY CYCLE To determine the worst-case inductor ...
Page 15
INPUT CAPACITOR SELECTION The bulk input capacitor provides a low impedance path for the inductor ripple current. Capacitor C1 in Figure 1 represents a bulk input capacitor. Choose a bulk input capacitor whose impedance at the switching frequency is lower ...
Page 16
ADP1621 The total power dissipation determines the diode junction temperature, which is given × θ DIODE A DIODE JA where T is the junction temperature, T J,DIODE perature, and θ is the ...
Page 17
RHP zero. The location of the RHP zero is determined by the following equation − × 2 LOAD π × RHP 2 L ...
Page 18
ADP1621 the external power MOSFET. Otherwise, R DSON represents the external current-sense resistor. Solving for R gives the slope-compensation criterion × + − × − × > ...
Page 19
Given the minimum on time of the ADP1621, pulse-skipping modulation is also a requirement to maintain output voltage regulation with light loads. During the short switching periods of pulse-skipping modulation, the MOSFET is turned on for the RECOMMENDED COMPONENT MANUFACTURERS ...
Page 20
ADP1621 LAYOUT CONSIDERATIONS Layout is important for all switching regulators, but is par- ticularly important for regulators with high switching frequencies. To achieve high efficiency, good regulation, and stability, a well- designed printed circuit board layout is required. A sample ...
Page 21
EFFICIENCY CONSIDERATIONS The efficiency, η dc/dc converter is given × OUT η 100 % P IN where P is the output power, and P OUT IN converter. While switching regulators are ideally lossless converters of ...
Page 22
ADP1621 EXAMPLES OF APPLICATION CIRCUITS STANDARD BOOST CONVERTER— DESIGN EXAMPLE The example covered here is for the ADP1621 configured as a standard boost converter, as shown in Figure 33, where lossless current sensing is employed. The design parameters are V ...
Page 23
BOOTSTRAPPED BOOST CONVERTER The inputs of the ADP1621 can be driven from the step-up converter output voltage to improve efficiency for low input voltages. For low input voltages, bootstrapped operation improves efficiency with heavy loads by increasing the available gate ...
Page 24
ADP1621 C3 1µF 10V C2 220pF f = 600kHz OSC C1 = MURATA GRM31CR60J476M C = RUBYCON 25ZL330M8x16 OUT2 L1 = COILCRAFT MSS1260-103ML C3 1µF 10V C2 220pF f = 600kHz OSC C1 = MURATA GRM31CR60J476M C = RUBYCON 25ZL330M8x16 ...
Page 25
Low Input and High Output Boost Converter Figure 36 shows a typical application boost converter circuit that operates at a switching frequency of 200 kHz with V and with load. The duty cycle ...
Page 26
ADP1621 C3 1µF 0.1µF 10V C2 120pF f = 560kHz OSC C1 = MURATA GRM32ER61C226K C = MURATA GRM31CR72A105K OUT1 C = MURATA GRM55ER71H475K OUT2 C = RUBYCON 63ZL220M10x23 OUT3 V = 12V 649Ω 15µ ...
Page 27
SEPIC CONVERTER CIRCUIT A single-ended primary inductance converter (SEPIC) topology is shown in Figure 39. This topology is useful for an unregulated input voltage, where the regulated output voltage falls within the input voltage range. The input and output are ...
Page 28
ADP1621 LED DRIVER APPLICATION CIRCUITS The ADP1621 can be used as an LED driver. Two LED application circuits are shown in Figure 41 and Figure 42, where each circuit is driving 20 white LEDs in series. Each white LED has ...
Page 29
R B 800Ω C3 0.1µF PIN IN GATE ADP1621 PWM SDSN CS COMP FB R COMP FREQ PGND 101kΩ GND C2 18pF C R COMP FREQ 390nF 50kΩ 1% AGND f = 400kHz OSC C1 = MURATA GRM31MR71E225K M1 = ...
Page 30
ADP1621 RELATED PARTS Table 6. Part Number Description ADP1610 Current-mode PWM step-up controller ADP1611 Current-mode PWM step-up controller Comments Maximum output = 12 V; PWM frequency = 700 kHz or 1.2 MHz; integrated 1.2 A, 0.2 Ω MOSFET power switch ...
Page 31
... OUTLINE DIMENSIONS ORDERING GUIDE Model Temperature Range 1 ADP1621ARMZ −40°C to +125°C 1 ADP1621ARMZ-R7 −40°C to +125°C ADP1621-EVAL Pb-free part. 3.10 3.00 2. 5.15 3.10 4.90 3.00 4.65 2. PIN 1 0.50 BSC 0.95 0.85 1.10 MAX 0.75 0.15 0.33 SEATING 0.23 0.05 PLANE ...
Page 32
ADP1621 NOTES ©2006 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D06090-0-12/06(A) Rev Page ...