General Description The MAX764 MAX765 MAX766 inverting switching regu lators are highly efficient over a wide range of load cur rents delivering up to 5W A unique current limited pulse frequency modulated PFM control scheme com bines the benefits of traditional PFM converters with the benefits of pulse width modulated PWM converters Like PWM converters the MAX764 MAX765 MAX766 are highly efficient at heavy loads Yet because they are PFM devices they use less than A of supply current vs 2mA to 10mA for a PWM device The input voltage range is 3V to 16V The output volt age is preset at 5V MAX764 12V MAX765 or 15V MAX766 it can also be adjusted from 1V to 16V using two external resistors Dual ModeTM The maxi mum operating VIN VOUT differential is 20V These devices use miniature external components their high switching frequencies up to 300kHz allow for less than 5mm diameter surface mount magnetics A stan dard H inductor is ideal for most applications so no magnetics design is necessary An internal power MOSFET makes the MAX764 MAX765 MAX766 ideal for minimum component count low and medium power applications For increased output drive capabil i ty or higher output voltages use the MAX774 MAX775 MAX776 or MAX1774 which drive an external power P channel MOSFET for loads up to 5W

Max Supply

Description

Niveau: Supérieur, Doctorat, Bac+8
_______________General Description The MAX764/MAX765/MAX766 inverting switching regu- lators are highly efficient over a wide range of load cur- rents, delivering up to 1.5W. A unique, current-limited, pulse-frequency-modulated (PFM) control scheme com- bines the benefits of traditional PFM converters with the benefits of pulse-width-modulated (PWM) converters. Like PWM converters, the MAX764/MAX765/MAX766 are highly efficient at heavy loads. Yet because they are PFM devices, they use less than 120µA of supply current (vs. 2mA to 10mA for a PWM device). The input voltage range is 3V to 16V. The output volt- age is preset at -5V (MAX764), -12V (MAX765), or -15V (MAX766); it can also be adjusted from -1V to -16V using two external resistors (Dual ModeTM). The maxi- mum operating VIN - VOUT differential is 20V. These devices use miniature external components; their high switching frequencies (up to 300kHz) allow for less than 5mm diameter surface-mount magnetics. A stan- dard 47µH inductor is ideal for most applications, so no magnetics design is necessary. An internal power MOSFET makes the MAX764/MAX765/ MAX766 ideal for minimum component count, low- and medium-power applications.

• load current


• limited


• off time


• supply voltage


• dc-dc inverters


• pfm converters


• toffminimum switch

Sujets

• Shutdown
• Supply
• Régulation
• Limited

Informations

• Publié par: profil-zyak-2012
• Nombre de lectures: 132
• Langue: English

Extrait

19-0176; Rev 0; 6/94

-5V/-12V/-15V or Adjustable,
High-Efficiency, Low I
Q
DC-DC Inverters
_______________General Description____________________________Features
The MAX764/MAX765/MAX766 inverting switching regu-
©
High Efficiency for a Wide Range of Load Currents
lators are highly efficient over a wide range of load cur-
rents, delivering up to 1.5W. A unique, current-limited,
©
250mA Output Current
pulse-frequency-modulated (PFM) control scheme com-
©
120µA Max Supply Current
bines the benefits of traditional PFM converters with the
benefits of pulse-width-modulated (PWM) converters.
©
5µA Max Shutdown Current
Like PWM converters, the MAX764/MAX765/MAX766 are
©
3V to 16V Input Voltage Range
highly efficient at heavy loads. Yet because they are PFM
devices, they use less than 120µA of supply current (vs.
©
-5V (MAX764), -12V (MAX765), -15V (MAX766),
2mA to 10mA for a PWM device).
or Adjustable Output from -1V to -16V
The input voltage range is 3V to 16V. The output volt-
©
Current-Limited PFM Control Scheme
age is preset at -5V (MAX764), -12V (MAX765), or -15V
(MAX766); it can also be adjusted from -1V to -16V
©
300kHz Switching Frequency
using two external resistors (Dual Mode
TM
). The maxi-
©
Internal, P-Channel Power MOSFET
mum operating V
IN
- V
OUT
differential is 20V.
These devices use miniature external components; their
______________Ordering Information
high switching frequencies (up to 300kHz) allow for less
than 5mm diameter surface-mount magnetics. A stan-
PARTTEMP. RANGEPIN-PACKAGE
dard 47µH inductor is ideal for most applications, so no
MAX764
CPA0°C to +70°C8 Plastic DIP
magnetics design is necessary.
MAX764CSA0°C to +70°C8 SO
An internal power MOSFET makes the MAX764/MAX765/
MAX764C/D0°C to +70°CDice*
MAX766ideal for minimum component count, low- and
MAX764EPA-40°C to +85°C8 Plastic DIP
medium-power applications. For increased output drive
MAX764ESA-40°C to +85°C8 SO
capability or higher output voltages, use the
MAX764MJA-55°C to +125°C8 CERDIP**
MAX774/MAX775/MAX776 or MAX1774, which drive an
external power P-channel MOSFET for loads up to 5W.
MAX765
CPA0°C to +70°C8 Plastic DIP
MAX765CSA0°C to +70°C8 SO
________________________Applications
MAX765C/D0°C to +70°CDice*
LCD-Bias Generators
MAX765EPA-40°C to +85°C8 Plastic DIP
Portable Instruments
MAX765ESA-40°C to +85°C8 SO
LAN Adapters
MAX765MJA-55°C to +125°C8 CERDIP**
Remote Data-Acquisition Systems
Ordering Information continued on last page.
Battery-Powered Applications
*** CDoicntea acrt ef atectsoteryd faotr Ta
A
va=il a+b2ili5t°y Ca, nDd Cp rpoacreasmsientegr tso oMnlIyL.-STD-883.
__________Typical Operating Circuit__________________Pin Configuration
3VI NTPOU 1T 5V
TOP VIEW
V+
OUTPUT
LX
-5V
OUT
18
LX
MAX764
FB
27
V+
ON/OFFSHDN47µHSHDN
3
MMAAXX776654
6
V+
REF
4
MAX766
5
GND
REFOUT
FBGND
DIP/SO

________________________________________________________________Maxim Integrated Products1
Call toll free 1-800-998-8800 for free samples or literature.

-5V/-12V/-15V or Adjustable,
High-Efficiency, Low IDC-DC Inverters
QABSOLUTE MAXIMUM RATINGS
V+ to GND..............................................................-0.3V to +17VOperating Temperature Ranges
OUT to GND...........................................................+0.5V to -17VMAX76_C_A ........................................................0°C to +70°C
Maximum Differential (V+ to OUT) ......................................+21VMAX76_E_A .....................................................-40°C to +85°C
REF, SHDN, FB to GND ...............................-0.3V to (V+ + 0.3V)MAX76_MJA ..................................................-55°C to +125°C
LX to V+..................................................................+0.3V to -21VMaximum Junction Temperatures
LX Peak Current ...................................................................1.5AMAX76_C_A/E_A ..........................................................+150°C
Continuous Power Dissipation (T= +70°C)MAX76_MJA .................................................................+175°C
APlastic DIP (derate 9.09mW/°C above +70°C) ............727mWStorage Temperature Range ............................-65°C to +160°C
SO (derate 5.88mW/°C above +70°C) .........................471mWLead Temperature (soldering, 10sec) ............................+300°C
CERDIP (derate 8.00mW/°C above +70°C) .................640mW
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
(V+ = 5V, I
LOAD
= 0mA, C
REF
= 0.1µF, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
V+ Input Voltage RangeV+MAX76_C/E3.016.0V
MAX76_M3.5
Supply CurrentI
S
V+ = 16V, SHDN < 0.4V90120
V+ = 16V, SHDN > 1.6V2µA
Shutdown CurrentI
SHDN
V+ = 10V, SHDN > 1.6V15
FB Trip Point3V
²
V+
²
16V-1010mV
MAX76_C±50
FB Input CurrentI
FB
MAX76_E±70nA
MAX76_M±90
MAX764, -4.8V
²
V
OUT
²
5.2V150260
Output Current and Voltage I
OUT
MAX765C/E, -11.52V
²
V
OUT
²
12.48V68120mA
(Note 1)MAX765M, -11.52V
²
V
OUT
²
12.48V50120
MAX766, -14.40V
²
V
OUT
²
-15.60V35105
MAX76_C1.47001.51.5300
Reference VoltageV
REF
MAX76_E1.46251.51.5375V
MAX76_M1.45501.51.5450
REF Load Regulation0µA
²
I
REF
²
100µAMAX76_C/E410mV
MAX76_M415
REF Line Regulation3V
²
V+
²
16V40100µV/V
Load Regulation (Note 2)0mA
²
I
LOAD
²
100mA0.008%/mA
Line Regulation (Note 2)4V
²
V+
²
6V0.12%/V
Efficiency (Note 2)10mA
²
I
LOAD
²
100mA,V
OUT
= -5V80%
V
IN
= 5VV
OUT
= -15V82
SHDN Leakage CurrentV+ = 16V, SHDN = 0V or V+±1µA
SHDN Input Voltage HighV
IH
3V
²
V+
²
16V1.6V
SHDN Input Voltage LowV
IL
3V
²
V+
²
16V0.4V

2_______________________________________________________________________________________

-5V/-12V/-15V or Adjustable,
High-Efficiency, Low I
Q
DC-DC Inverters
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 5V, I
LOAD
= 0mA, C
REF
= 0.1µF, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
MAX76_C±5
LX Leakage Current
I
LX
I
+ (V+)
²
20VMAX76_E±10µA
MAX76_M±30
LX On-Resistance
I
V
OUT
I
+ (V+)
³
10V1.42.5
½
Peak Current at LXI
PEAK
I
V
OUT
I
+ (V+)
³
10V0.50.75A
Maximum Switch On-Timet
ON
121620µs
Minimum Switch Off-Timet
OFF
1.82.32.8µs
Note 1:
See Maximum Output Current vs. Supply Voltage graph in the Typical Operating Characteristics. Guarantees are based on
correlation to switch on-time, switch off-time, on-resistance, and peak current rating.
Note 2:
Circuit of Figure 2.

__________________________________________Typical Operating Characteristics
(V+ = 5V, V= -5V, T= +25°C, unless otherwise noted.)
ATUO

MAX764 MAX765 MAX766
EFFICIENCY vs. LOAD CURRENTEFFICIENCY vs. LOAD CURRENTEFFICIENCY vs. LOAD CURRENT
100100100
90V+ = 5V90V+ = 8V90
808080
7070V+ = 5V70V+ = 5V
60V+ = 10V6060
505050
404040
30V+ = 15V3030
202020
10CIRCUIT OF FIGURE 2 10CIRCUIT OF FIGURE 2 10CIRCUIT OF FIGURE 2
V
OUT
= -5V ±4%V
OUT
= -12V ±4%V
OUT
= -15V ±4%
0000.111010010000.111010010000.11101001000
LOAD CURRENT (mA)LOAD CURRENT (mA)LOAD CURRENT (mA)

_______________________________________________________________________________________3

-5V/-12V/-15V or Adjustable,
High-Efficiency, Low I
Q
DC-DC Inverters
____________________________Typical Operating Characteristics (continued)
(V+ = 5V, V
OUT
= -5V, T
A
= +25°C, unless otherwise noted.)
MAXIMUM OUTPUT CURRENT NO-LOAD SUPPLY CURRENT NO-LOAD SUPPLY CURR