MAX1820XEUB+T Maxim Integrated Products, MAX1820XEUB+T Datasheet
MAX1820XEUB+T
Specifications of MAX1820XEUB+T
Related parts for MAX1820XEUB+T
MAX1820XEUB+T Summary of contents
Page 1
... Hand-Held Instruments Typical Operating Circuits continued at end of data sheet. Ordering Information continued at end of data sheet. Pin Configurations appear at end of data sheet. UCSP is a trademark of Maxim Integrated Products, Inc. µMAX is a registered trademark of Maxim Integrated Products, Inc. SYNC PART FREQ (MHz) No Sync MAX1820ZEBC* 19 ...
Page 2
WCDMA Cellular Phone 600mA Buck Regulators ABSOLUTE MAXIMUM RATINGS BATT, OUT (FB), SHDN, SYNC, SKIP, REF to GND .......................................................-0.3V to +6.0V PGND to GND .......................................................-0.3V to +0.3V LX, COMP to GND...................................-0. Output Short-Circuit Duration ............................................Infinite Continuous Power Dissipation ...
Page 3
ELECTRICAL CHARACTERISTICS (continued) = 3.6V, SHDN = BATT, SKIP = SYNC = GND BATT Typical values are +25°C.) (Note 2) A PARAMETER SYMBOL CONTROLLER P-Channel On-Resistance N-Channel On-Resistance Current-Sense Transresistance P-Channel Current-Limit Threshold P-Channel Pulse-Skipping ...
Page 4
WCDMA Cellular Phone 600mA Buck Regulators ELECTRICAL CHARACTERISTICS = 3.6V, SHDN = BATT, SKIP = SYNC = GND BATT (Notes 2, 3) PARAMETER SYMBOL Input BATT Voltage V Undervoltage Lockout V UVLO Threshold Quiescent Current I Quiescent Current ...
Page 5
ELECTRICAL CHARACTERISTICS (continued) = 3.6V, SHDN = BATT, SKIP = SYNC = GND BATT (Notes 2, 3) PARAMETER SYMBOL LX Leakage Current Maximum Duty Cycle duty Minimum Duty Cycle duty SYNC AND OSCILLATOR SYNC Divide Ratio (MAX1820X) SYNC ...
Page 6
WCDMA Cellular Phone 600mA Buck Regulators (T = +25°C, unless otherwise noted.) A MAX1821 EFFICIENCY vs. LOAD CURRENT (V = 3.3V) OUT 100 ...
Page 7
A LIGHT-LOAD SKIP-SWITCHING WAVEFORMS (V = 4.2V LOAD = 30mA, SKIP = GND s/div 5V/div LX B: INDUCTOR CURRENT, 500mA/div C: V (AC-COUPLED), 20mV/div OUT ...
Page 8
WCDMA Cellular Phone 600mA Buck Regulators (T = +25°C, unless otherwise noted.) A OUTPUT SWITCHING HARMONICS vs. FREQUENCY (V = 3.8V 3.4V OUT 1.6 1.2 0.8 0.4 0 0.1 1 FREQUENCY (MHz) OUTPUT SWITCHING HARMONICS vs. ...
Page 9
PIN MAX1820 MAX1820 MAX1821 UCSP µMAX UCSP — — — — — _______________Detailed Description The MAX1820/MAX1821 PWM step-down ...
Page 10
WCDMA Cellular Phone 600mA Buck Regulators BATT 1.25V VOLTAGE REFERENCE GND TRANSIMPEDANCE ERROR AMP OUT REF MAX1820 Figure 1. MAX1820 Simplified Functional Diagram (No SYNC for MAX1820Z) BATT 1.25V VOLTAGE REFERENCE GND TRANSIMPEDANCE OUT REF MAX1821 Figure 2. MAX1821 Simplified ...
Page 11
V = 2. CAN BE OMITTED IF CERAMIC OUTPUT CAPACITOR IS USED. Figure 3. Standard Operating Circuit the load. The duty cycle of a buck step-down converter is ideally a ratio of the output ...
Page 12
WCDMA Cellular Phone 600mA Buck Regulators Forced PWM operation uses higher supply current with no load (3.3mA typ) compared to skip mode. 100% Duty-Cycle Operation The on-time can exceed one internal oscillator cycle, which permits operation up to 100% duty ...
Page 13
Applications Information Setting the Output Voltage (MAX1820) The MAX1820 is optimized for highest system efficiency when applying power to a linear PA in WCDMA hand- sets. When transmitting at less than full power, the sup- ply voltage to the PA ...
Page 14
WCDMA Cellular Phone 600mA Buck Regulators Table 1. Suggested Inductors MANUFACTURER PART NUMBER Coilcraft DO1606 Coilcraft LPT1606-472 Sumida CDRH4D18-4R7 Sumida CR43 Sumida CDRH5D18-4R1 3) Calculate the equivalent load impedance OUT(MAX OUT(MAX) 4) Calculate the compensation ...
Page 15
Output Capacitor Selection The output capacitor is required to keep the output volt- age ripple small and to ensure regulation control loop stability. The output capacitor must have low imped- ance at the switching frequency. Ceramic capacitors are recommended. The ...
Page 16
WCDMA Cellular Phone 600mA Buck Regulators SYNC PART OUTPUT VOLTAGE FREQ (MHz) No Sync MAX1821EBC* No Sync MAX1821EUB 13 MAX1821XEBC* 13 MAX1821XEUB *UCSP reliability is integrally linked to the user’s assembly methods, circuit board material, and environment. Refer to the ...
Page 17
For the latest package outline information www.maxim-ic.com/packages.) ______________________________________________________________________________________ WCDMA Cellular Phone 600mA Buck Regulators Package Information PACKAGE OUTLINE, 4x3 UCSP 21-0104 ...
Page 18
... 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. 18 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2005 Maxim Integrated Products ...