MAX1611CSE ,Digitally Controlled CCFL Backlight Power SuppliesApplications______________Ordering InformationNotebook/Laptop ComputersPART TEMP. RANGE PIN-PACKAGE ..
MAX1614EUA ,High-Side / N-Channel MOSFET Switch DriverELECTRICAL CHARACTERISTICS(V = 15V, T = 0°C to +85°C, unless otherwise noted. Typical values are at ..
MAX1614EUA ,High-Side / N-Channel MOSFET Switch Driverfeatures a 1.5%-accurate low-batterycomparator that can be used to indicate a low-battery' Space-Sa ..
MAX1614EUA+ ,High-Side, n-Channel MOSFET Switch DriverElectrical Characteristics(V = 15V, T = 0°C to +85°C, unless otherwise noted. Typical values are at ..
MAX1614EUA+T ,High-Side, n-Channel MOSFET Switch DriverApplicationsPART TEMP RANGE PIN-PACKAGE● Notebook ComputersMAX1614C/D 0°C to +70°C Dice*● Portable ..
MAX1614EUA-T ,High-Side, n-Channel MOSFET Switch Driverfeatures a 1.5%-accurate low-battery ● Low Power Consumption Extends Battery Life comparator that c ..
MAX4322ESA+ ,Single/Dual/Quad, Low-Cost, UCSP/SOT23, Low-Power, Rail-to-Rail I/O Op AmpsELECTRICAL CHARACTERISTICS—T = +25°C (continued)A(V = 5V, V = 0V, V = 0V, V = V /2, SHDN = V R conn ..
MAX4322EUK ,Single/Dual/Quad, Low-Cost, UCSP/SOT23, Low-Power, Rail-to-Rail I/O Op AmpsFeaturesThe MAX4322/MAX4323/MAX4326/MAX4327/MAX4329♦ 6-Bump UCSP Package (MAX4323)family of operati ..
MAX4322EUK ,Single/Dual/Quad, Low-Cost, UCSP/SOT23, Low-Power, Rail-to-Rail I/O Op AmpsApplicationsMAX4323Battery-Powered Data-Acquisition Instruments Systems2 IN- OUTRSSI Systems Signal ..
MAX4322EUK ,Single/Dual/Quad, Low-Cost, UCSP/SOT23, Low-Power, Rail-to-Rail I/O Op AmpsMAX4322/MAX4323/MAX4326/MAX4327/MAX432919-1380; Rev 3; 10/02Single/Dual/Quad, Low-Cost, UCSP/SOT23, ..
MAX4322EUK+T ,Single/Dual/Quad, Low-Cost, UCSP/SOT23, Low-Power, Rail-to-Rail I/O Op AmpsApplicationsMAX4323Battery-Powered Data-Acquisition Instruments Systems2 IN- OUTRSSI Systems Signal ..
MAX4322EUK-T ,Single/Dual/Quad / Low-Cost / SOT23 / Low-Power / Rail-to-Rail I/O Op AmpsELECTRICAL CHARACTERISTICS—T = +25°C A(V = +5.0V, V = 0, V = 0, V = V / 2, SHDN = V R tied to V / 2 ..
MAX1610CSE-MAX1611CSE
Digitally Controlled CCFL Backlight Power Supplies
MAX1610/MAX1611
Digitally Controlled CCFL Backlight
Power Supplies
_______________General DescriptionThe MAX1610/MAX1611 are fully integrated, high-
efficiency drivers for cold-cathode fluorescent lamps
(CCFLs). They operate from a 4.5V to 26V power
source. An on-board, high-switching-frequency power
MOSFET reduces external component count and mag-
netics size. The MAX1610/MAX1611 protect against
open or shorted lamps. The CCFL can be driven from
an isolated transformer secondary winding to improve
efficiency and avoid flicker at dim tube settings.
Brightness is adjusted by scaling the lamp current, or
by operating with a fixed lamp current and chopping
the CCFL on and off at a rate faster than the eye can
detect.
The MAX1610’s digital inputs increment, decrement, or
clear an internal, 5-bit up/down counter, which sets
CCFL brightness. The MAX1611 uses a System
Management Bus (SMBus) 2-wire serial interface to
directly set CCFL brightness. Both devices include
micropower shutdown and a linear regulator that elimi-
nates the need for a separate logic supply. The digital
interface remains active in shutdown, preserving the
brightness setting.
________________________ApplicationsNotebook/Laptop Computers
Point-of-Sale Terminals
Portable Medical Equipment
Instrument Displays
____________________________FeaturesDirect Digital Control of CCFL BrightnessLow Supply Current: 3mA Max Operating
20µA Max ShutdownLow-Voltage Operation, Down to 4.5VInternal 26V, 0.7WPower SwitchProtection Against Open or Shorted LampsSupports Isolated Transformer Secondary
WindingSMBus Serial Interface (MAX1611)No Flicker at Low Brightness (internal 280Hz
current chopping)High Power-to-Light EfficiencySelectable 290kHz/145kHz Switching FrequencyOscillator SYNC Input16-Pin Narrow SO Package
__________________________________________________________Pin Configurations
MAX1610/MAX1611
Digitally Controlled CCFL Backlight
Power Supplies
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(TA= 0°C to +70°C, BATT = 8.2V, MINDAC = 0V, unless otherwise noted. Typical values are at TA= +25°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.
BATT to GND............................................................-0.3V to 28V
BST to GND..............................................................-0.3V to 30V
BST to LX....................................................................-0.3V to 6V
LX to GND................................................-0.6V to (BATT + 0.3V)
VL to GND...................................................................-0.3V to 6V
CS, CSAV, CC, SYNC, REF, MINDAC,
SS, OTP to GND............................................-0.3V to (VL + 0.3V)
SHDN, UP, DN to GND...............................................-0.3V to 6V
SMBSUS, SDA, SCL to GND......................................-0.3V to 6V
BATT, LX Current.....................................................................1A
SDA Current........................................................................50mA
VL Current...........................................................................50mA
Continuous Power Dissipation (TA= +70°C)
SO (derate 8.70mW/°C above +70°C).........................696mW
Operating Temperature Range
MAX1610CSE/MAX1611CSE..............................0°C to +70°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10sec).............................+300°C
MAX1610/MAX1611
Digitally Controlled CCFL Backlight
Power Supplies
ELECTRICAL CHARACTERISTICS (continued)(TA= 0°C to +70°C, BATT = 8.2V, MINDAC = 0V, unless otherwise noted. Typical values are at TA= +25°C.)
MAX1610/MAX1611
Digitally Controlled CCFL Backlight
Power Supplies
Note 1:Guaranteed by design.
TIMING CHARACTERISTICS—MAX1611 (Figures 2 and 3, TA= +25°C, unless otherwise noted.)
TIMING CHARACTERISTICS—MAX1610 (Figure 1, TA= +25°C, unless otherwise noted.)
MAX1610/MAX1611
Digitally Controlled CCFL Backlight
Power SuppliesBATT SUPPLY CURRENT
vs. BATT VOLTAGE (SHDN = VL)
MAX1610/1611-TOC2
BATT (V)
BATT CURRENT (mA)
BATT SUPPLY CURRENT
vs. BATT VOLTAGE (SHDN = OV)
MAX1610/1611-TOC5
BATT (V)
BATT CURRENT (12162024288
VL OUTPUT VOLTAGE
vs. BATT VOLTAGE (SHDN = OV)
MAX1610/1611-TOC6
BATT (V)
VL (V)
VL OUTPUT VOLTAGE
vs. VL OUTPUT CURRENT
MAX1610/1611-TOC3
VL OUTPUT CURRENT (mA)
VL VOLTAGE (V)
VL OUTPUT VOLTAGE
vs. VL LOAD CURRENT
MAX1610/1611-TOC4
VL LOAD CURRENT (μA)
VL VOLTAGE (V)
REF OUTPUT VOLTAGE
vs. REF OUTPUT CURRENT
MAX1610/1611-TOC1
REF OUTPUT CURRENT (µA)
REF OUTPUT VOLTAGE (V)
VL OUTPUT VOLTAGE
vs. BATT VOLTAGE (SHDN = VL)
MAX1610/1611-TOC7
BATT (V)
VL (V)
__________________________________________Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
MAX1610/MAX1611
Digitally Controlled CCFL Backlight
Power Supplies
______________________________________________________________Pin Description
MAX1610/MAX1611
Digitally Controlled CCFL Backlight
Power SuppliesFigure 1. MAX1610 UP and DN Signal Timing
Figure 2. MAX1611 SMB Serial-Interface Timing—Address
_______________Detailed Description
Getting StartedA cold-cathode fluorescent lamp (CCFL) has two termi-
nals. For the CCFL to emit light, the two lamp terminals
must be driven with a high-voltage (approximately
550V AC RMS) and high-frequency (approximately
45kHz) sine wave. The MAX1610/MAX1611 use a vary-
ing DC input voltage to create this high-voltage, high-
frequency sine-wave drive. To select the correct
component values for the MAX1610/MAX1611 circuit,
several CCFL parameters and the minimum DC input
voltage must be specified; these are listed in Table 1.
Table 3 shows the recommended component values to
use with the circuit of Figure 4, depending on the par-
ticular CCFL parameters. The C2 values in Table 3
have been selected such that the normal operating
voltage on the secondary of T1 is as close as possible
to the CCFL strike voltage (where the strike voltage
(VS) is assumed to be approximately 1.8 times the
CCFL operating voltage (VL)).
Components T1, C1, R2, Q1, and Q2 form a Royer
oscillator. A Royer oscillator is a resonant tank circuit
that oscillates at a frequency dependent on C1, the pri-
mary magnetizing inductance of T1 (LP), and the
impedance seen by the T1 secondary. The
MAX1610/MAX1611 regulate the current fed into the
Royer oscillator by sensing the voltage on R1. For a
given current through the Royer oscillator (IR1), the
power delivered to the CCFL depends on the Royer
oscillator frequency. The R1 values in Table 3 have
been selected to ensure that the power into the CCFL
does not exceed its maximum rating, despite T1, C1, and
C2 component-value variations. The Royer oscillator
waveforms for the circuit of Figure 4 are shown in Figures
5 and 6.
Analog CircuitryThe MAX1610/MAX1611 maintain fixed CCFL bright-
ness with varying input voltages on BATT by regulating
the current fed into the Royer oscillator. This current is
sensed via resistor R1 between CSAV and GND. An
internal switch from BATT-to-LX pulse-width modulates
at a fixed frequency to servo the CSAV pin to its regula-
tion voltage. The CSAV regulation voltage can be
adjusted via the digital interface to set CCFL bright-
ness. The MAX1610 and MAX1611 differ only in the
digital interface they use to adjust the internal 5-bit digi-
tal-to-analog converter (DAC) that sets the CSAV regu-
lation voltage. The minimum-scale (min-scale) CSAV
regulation voltage is resistor adjustable using the MIN-
DAC pin, setting the minimum CCFL brightness. The
D/A setting at MAX1610/MAX1611 power-up is preset
to mid-scale (10000 binary) (Figure 7).
MINDAC Sets the Minimum ScaleThe MINDAC pin sets the lowest CCFL brightness
level. The voltage at MINDAC is divided by eight, and
sets the minimum CSAV regulation voltage. For exam-
ple, in the circuit of Figure 4, R5 (150kΩ) and R6
(51kΩ) form a resistor divider from REF, which sets
MINDAC to 507mV (REF = 2.0V). This sets a minimum
CSAV regulation voltage of 63mV with a full-scale
CSAV regulation voltage of 247mV.
MAX1610/MAX1611
Digitally Controlled CCFL Backlight
Power SuppliesFigure 3. MAX1611 SMB Serial-Interface Timing—Acknowledge
MAX1610/MAX1611
Digitally Controlled CCFL Backlight
Power Supplies
Table 1. Necessary CCFL SpecificationsFigure 4. Typical Floating-Lamp Application Circuit
MAX1610/MAX1611
Digitally Controlled CCFL Backlight
Power Supplies
b) Capacitors
c) Other Components
Note:Component values depend on lamp characteristics. See Table 3 to select values.
Note:fROY= Royer oscillator damped resonant oscillation frequency. T1 primary magnetizing inductance (LP) = 44µH ±20%.
VCT = average voltage from the T1 center tap to the emitters of Q1 and Q2 (ignoring Q1, Q2 VCE,SAT).
C1 = 0.1µF ±20%; C2 = ±10% tolerance; R1 = ±1% tolerance.
Table 3. Selecting Circuit Values for Figure 4
Table 2. Typical Application Circuit Component Values
a) Resistors
