|
|
Part: MAX679
Category:
Analog & Mixed-Signal Processing
-> Power
Description: Regulated 3.3V Charge Pump
Company: Maxim Integrated Products
Datasheet: Download MAX679 datasheet File size : 256 kB
Request For quote: Find where to buy MAX679
Datasheet text preview:
19-1217; Rev 0; 4/97
Regulated 3.3V Charge Pump
_______________General Description
The MAX679 step-up, regulated charge pump generates a 3.3V ±4% output voltage from a 1.8V to 3.6V i n p u t voltage (two alkaline, NiCd, or NiMH; or one Lithium-Ion battery). Output current is 20mA (min) from a 2.0V input. Only three external capacitors are needed to build a complete DC-DC converter. The MAX679's switching frequency is pin selectable at 330kHz or 1MHz to allow trade-offs between lowest supply current and smallest-size capacitors. The logic shutdown function reduces the supply current to 5µA (max) and disconnects the load from the input. Special s o f t - s t a r t circuitry prevents excessive current from being drawn from the battery during start-up. This DCDC converter requires no inductors and has low EMI. It is available in the ultra-small µMAX package, which is only 1.11mm high and half the area of an 8-pin SO.
____________________________Features
o Regulated 3.3V ±4% Output o Ultra-Small: 1.1mm-High, 8-Pin µMAX Package o No Inductors Required o Up to 1MHz Operation (small external components) o Fits into 0.05 in.2 o Up to 85% Efficiency o 1.8V to 3.6V Input Voltage Range o 50µA Quiescent Supply Current o 1µA Shutdown Current
MAX679
________________________Applications
Battery-Powered Applications Miniature Equipment Backup-Battery Boost Converters Translators Two-Way Pagers
______________Ordering Information
PART MAX679C/D MAX679EUA TEMP. RANGE 0°C to +70°C -40°C to +85°C PIN-PACKAGE Dice* 8 µMAX
*Dice are tested at TA = +25°C only.
__________Typical Operating Circuit
INPUT 2V to 3.6V IN CIN OUT COUT
__________________Pin Configuration
OUTPUT 3.3V, 20mA
TOP VIEW
MAX679
FSET SHDN OFF/ON PGND GND C1C1+
FSET 1 SHDN 2
8 7
OUT C1+ C1PGND
MAX679
IN 3 C1 GND 4 5 6
µMAX
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
Regulated 3.3V Charge Pump MAX679
ABSOLUTE MAXIMUM RATINGS
IN, OUT, SHDN, FSET to GND...-0.3V to 6V PGND to GND............±0.3V C1- to GND ........-0.3V to (VIN + 0.3V) C1+ to GND....-0.3V to (VOUT + 0.3V) OUT Short to GND .....10sec Continuous Power Dissipation (TA = +70°C) µMAX (derate 4.1mW/°C above +70°C) .....330mW Operating Temperature Range ...-40°C to +85°C Storage Temperature Range .....-65°C to +160°C Lead Temperature (soldering, 10sec) .....+300°C
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VIN = V S HDN = VFSET = 2V, CIN = 4.7µF, C1 = 0.33µF, COUT = 10µF, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Input Voltage Input Undervoltage Lockout Voltage Output Voltage Output Current No-Load Supply Current 2V 3.17V VIN = 2.5V, FSET = IN or GND TA = 0°C to +85°C TA = -40°C to +85°C CONDITIONS MIN 1.8 0.8 3.17 3.15 20 50 15 1 0.5 x VIN 0.7 x VIN 0.5 x VIN 0.1 260 700 330 1000 100 80 1 450 kHz FSET = IN Output Short-Circuit Current Efficiency OUT = GND, VIN = 3.3V VIN = 2V, IOUT = 10mA 1300 200 mA % 80 25 5 0.3 x VIN 3.3 TYP MAX 3.6 1.6 3.43 V 3.45 mA µA µA µA V V µA UNITS V V
Leakage Current into OUT in Shutdown VOUT = 3.6V, SHDN = GND Supply Current in Shutdown FSET, SHDN Input Voltage Low FSET, SHDN Input Voltage High FSET, SHDN Input Leakage Current Switching Frequency VIN = 3.3V VIN = 1.8V VIN = 3.6V FSET, S H D N = GND or VIN FSET = GND
Note 1: Specifications to -40°C are guaranteed by design, not production tested.
2
_______________________________________________________________________________________
Regulated 3.3V Charge Pump
__________________________________________Typical Operating Characteristics
(Typical Operating Circuit with: VIN = V S HDN = 2V, CIN = 4.7µF, C1 = 0.33µF, COUT = 10µF, tested in-circuit, TA = +25°C, unless otherwise noted.)
EFFICIENCY vs. OUTPUT CURRENT
MAX679 TOC01a
MAX679
EFFICIENCY vs. OUTPUT CURRENT
MAX679 TOC01b
OUTPUT VOLTAGE vs. OUTPUT CURRENT
FSET = GND (330kHz) 3.5 3.4 OUTPUT VOLTAGE (V) 3.3 3.2 3.1 3.0 2.9 VIN = 1.8V DASHED LINES INDICATE OUTPUT OUT OF REGULATION 0 10 20 30 40 50 60 70 80 VIN = 2.0V VIN = 2.4V VIN = 3.5V VIN = 3.0V
MAX679 TOC02a
100 90 80 70 EFFICIENCY (%) 60 50 40 30 20 10 0 0.01 0.1 1 10 FSET = IN (1MHz) VIN = 3.0V VIN = 3.5V VIN = 2.0V VIN = 1.8V
100 90 80 70 EFFICIENCY (%) 60 50 40 30 20 10 0 FSET = GND (330kHz) VIN = 3.5V VIN = 2.0V VIN = 2.4V VIN = 3.0V VIN = 1.8V
3.6
VIN = 2.4V
2.8 0.01 0.1 1 10 100 OUTPUT CURRENT (mA) OUTPUT CURRENT (mA)
100
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE vs. OUTPUT CURRENT
MAX679 TOC02b
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX679 TOC05
SHUTDOWN SUPPLY CURRENT vs. TEMPERATURE
VIN = 2.4V SHUTDOWN SUPPLY CURRENT (nA) 500 400 300 200 100 0
MAX679 TOC06
3.4 FSET = IN (1MHz) 3.3 OUTPUT VOLTAGE (V) VIN = 3.0V 3.2 VIN = 2.4V 3.1 VIN = 1.8V VIN = 2.0V VIN = 3.5V
100 SHDN = IN SUPPLY CURRENT (µA)
600
10
1
SHDN = GND
3.0 DASHED LINES INDICATE OUTPUT OUT OF REGULATION 2.9 0 10 20 30 40 50 60 70 80 90 100 OUTPUT CURRENT (mA) 0.1 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 SUPPLY VOLTAGE (V)
-40
-15
10
35
60
85
TEMPERATURE (°C)
PUMP FREQUENCY vs. TEMPERATURE
MAX679 TOC08a
PUMP FREQUENCY vs. TEMPERATURE
MAX679 TOC08b
OUTPUT RIPPLE (2mA LOAD)
FSET = GND (330kHz)
MAX679 TOC09
360 350 PUMP FREQUENCY (kHz) 340 330 320 310 300 -40 -15 10 35 60 FSET = GND (330kHz) VIN = 2.5V
1100 1080 1060 PUMP FREQUENCY (kHz) 1040 1020 1000 980 960 940 920 900 FSET = IN (1MHz) VIN = 2.5V
VOUT 50mV/div AC COUPLED
85
-40
-15
10
35
60
85
100µs/div
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
3
Others parts begin by ma
|
|
|
