Rainbow Electronics MAX1664 User Manual
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
________________General Description
The MAX1664 integrates power-supply and backplane
drive circuitry for active-matrix thin-film-transistor (TFT) liquid crystal displays. Included are a single-output, pulsewidth-modulation boost converter (0.25Ω switch), a
dual-output (positive and negative) gate-driver supply
using one inductor, an LCD backplane driver, and a simple phase-locked loop to synchronize all three outputs.
High switching frequency (1MHz nominal) and phaselocked operation allow the use of small, minimumheight external components while maintaining low
output noise. A +2.8V to +5.5V input voltage range
allows operation with any logic supply. Output voltages
are adjustable to +5.5V (DC-DC 1) and to +28V and
-10V (DC-DC 2). The negative output voltage can be
adjusted to -20V with additional components. Also
included are a logic-level shutdown and a “Ready” output (RDY) that signals when all three outputs are in regulation.
The boost-converter operating frequency can be set at
16, 24, or 32 times the backplane clock. This flexibility
allows a high DC-DC converter frequency to be used
with LCD backplane clock rates ranging from 20kHz to
72kHz. The MAX1664 is supplied in a 1.1mm-high
TSSOP package.
________________________Applications
LCD Modules
LCD Panels
____________________________Features
♦ Integrates All Active Circuitry for Three DC-DC
Converters
♦ Ultra-Small External Components
(ceramic capacitors, 2µH to 5µH inductors)
♦ DC-DC Converters Phase-Locked to Backplane
Frequency for Lowest Noise
♦ Low Operating Voltage (down to +2.8V)
♦ Adjustable Output Voltage from V
IN
to +5.5V
♦ Load Currents Up to 500mA
♦ Adjustable TFT Gate Driver Output:
Positive, V
IN
to +28V
Negative, 0 to -10V (-20V with added
components)
♦ Includes 0.35Ω Backplane Driver
♦ 1µA Shutdown Current
♦ Power-Ready Output Signal
MAX1664
________________________________________________________________
Maxim Integrated Products
1
REF
FB2-
IN INP
LX2P
LX2N
FB2+
PGND2
PLLC
GND
FPLL
RDY
REF
SHDN
ON
OFF
5.5V
-10V
28V
BPV
SS
BACKPLANE
DRIVER
V
SUPPLY
2.8V TO 5.5V
BPDRV
BPV
DD
PGND1
FB1
LX1
BPCLK
MAX1664
Typical Operating Circuit
___________________Pin Configuration
19-1356; Rev 0; 4/98
PART
MAX1664CUP 0°C to +70°C
TEMP. RANGE PIN-PACKAGE
20 TSSOP
_______________Ordering Information
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
FPLL
LX1
PGND1
PGND2REF
FB1
RDY
SHDN
TOP VIEW
LX2N
LX2P
INP
BPCLKFB2+
FB2-
IN
GND
12
11
9
10
BPV
DD
BPDRVBPV
SS
PLLC
MAX1664
TSSOP
Active-Matrix Liquid Crystal Display
(AMLCD) Supply
MAX1664
Active-Matrix Liquid Crystal Display
(AMLCD) Supply
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN= V
INP
= 3.3V, SHDN = IN, V
BPVDD
= 4V, V
BPVSS
= -1V, PGND1 = PGND2 = FPLL = GND, f
BPCLK
= 30kHz, TA= 0°C to +70°C,
unless otherwise noted. Typical values are at T
A
= +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.
RDY, IN, BPVDDto GND...........................................-0.3V to +6V
FB2-, PGND1, PGND2 to GND ..........................................±0.3V
LX1 to PGND1..........................................................-0.3V to +6V
BPV
SS
to GND.......................................................-3.3V to +0.3V
BPVDD to BPV
SS
......................................................-0.3V to +6V
BPDRV to BPV
SS
..................................-0.3V to (V
BPVDD
+ 0.3V)
LX2P to INP ............................................................-15V to +0.3V
LX2N to PGND2......................................................-0.3V to +30V
SHDN, INP, FB1, FB2+, REF, PLLC,
BPCLK, FPLL to GND................................-0.3V to (V
IN
+0.3V)
RDY Sink Current................................................................20mA
LX2P, LX2N Peak Switch Currents.................................±750mA
Continuous Power Dissipation (TA= +70°C)
20-Pin TSSOP (derate 7mW/°C above+70°C) ..............559mW
Operating Temperature Range...............................0°C to +70°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10sec).............................+300°C
FPLL = IN
FPLL = REF
FPLL = GND
Rising edge, 2% hysteresis
V
LX1
= 6V
FPLL = REF
FPLL = GND
V
FB1
= 1.3V
V
FB1+
= V
FB2+
= 1.3V, V
FB2-
= -0.1V;
IIN+ I
INP
SHDN = GND, VIN= 5.5V; IIN+ I
INP
FPLL = IN
CONDITIONS
8 x f
BPCLK
12 x f
BPCLK
Hz
16 x f
BPCLK
f
OP2(MAX)
Maximum Operating Frequency
V-10 0V
OUT2-
Negative Output Voltage Range
VV
IN
28V
OUT2+
Positive Output Voltage Range
V1.091 1.125 1.159V
TH_RDY
Power-Ready Trip Level
A1.2 1.5 1.8I
LIM(LX1)
LX1 Peak Current Limit
µA0.1 10I
LKG(LX1)
LX1 Leakage Current
Ω0.25 0.5R
ON(LX1)
LX1 On Resistance
nA100I
FB1
FB1 Input Bias Current
16 x f
BPCLK
Operating Frequency
V2.5 2.8V
UVLO
V2.8 5.5V
IN
Input Supply Range
Undervoltage Lockout
Threshold
24 x f
BPCLK
Hz
32 x f
BPCLK
f
OP1
VV
IN
5.5V
OUT1
Output Voltage Range
mA0.5 2I
Q
Quiescent Current
µA0.01 10I
SD
Shutdown Current
UNITSMIN TYP MAXSYMBOLPARAMETER
0 < I
LX1
< 1.2A V1.2125 1.2500 1.275V
FB1
FB1 Regulation Voltage
DC-DC 1 (PWM MAIN OUTPUT)
DC-DC 2 (PFM)
MAX1664
Active-Matrix Liquid Crystal Display
(AMLCD) Supply
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VIN= V
INP
= 3.3V, SHDN = IN, V
BPVDD
= 4V, V
BPVSS
= -1V, PGND1 = PGND2 = FPLL = GND, f
BPCLK
= 30kHz, TA= 0°C to +70°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
V
BPCLK
= 0 or 3.3V
SHDN = GND
Source and sink
Rising edge, 40mV hysteresis
SHDN = GND
Falling edge, 40mV hysteresis
V
LX2N
= 28V, V
LX2P
= -10V
V
FB2+
= 1.3V, V
FB2-
= -0.1V
CONDITIONS
µA0.01 1I
IN(BPCLK)
BPCLK Input Current
V0.7 x V
IN
V
IH(BPCLK)
BPCLK Input High Voltage
V0.3 x V
IN
V
IL(BPCLK)
BPCLK Input Low Voltage
µA80 200I
IN(BPVDD)
BPVDDSupply Current
µA-10 10I
LKG(BPDRV)
BPDRV Leakage Current
Ω0.35 0.7R
ON(BPDRV)
BPDRV On-Resistance
µA0.1 10I
SHDN(BP)
BPVDDShutdown Current
V2.5 5.5V
VDD to VSS
BPVDDto BPVSSVoltage
Range
V-3 0V
BPVSS
BPVSSSupply Range
V2.5 5.5V
BPVDD
BPVDDSupply Range
mV-15 0 15V
FB2-
V1.225 1.25 1.275V
FB2+
FB2+ Regulation Voltage
FB2- Regulation Voltage
V1.091 1.125 1.159V
TH(RDY)
FB2+ Power-Ready Trip Level
mV85 120 165V
TH(RDY)
FB2- Power-Ready Trip Level
µA0.05 10
I
LKG(LX2N)
,
I
LKG(LX2P)
LX2N, LX2P Leakage Current
nA-100 100
I
FB2+
,
I
FB2-
FB2+, FB2- Input Bias Current
Ω0.9 1.7
R
ON(LX2N)
,
R
ON(LX2P)
LX2N, LX2P On-Resistance
UNITSMIN TYP MAXSYMBOLPARAMETER
C
PLLC
= 22nF
R
PLLC
= 100kΩ
C
SHUNT
= 2.2nF
PLLC = REF, BPCLK = GND
40 72
BPCLK Input Frequency
Range
27 48 kHz
20 36
f
BPCLK
MHz1.63 1.92 2.20f
C
VCO Center Frequency
(Note 1)
-2µA < I
REF
< 50µA
V0.90 1.05 1.20V
REF(UVLO)
Undervoltage Lockout
V1.225 1.250 1.275V
REF
Reference Voltage
(0.10 x VIN) typical hysteresis V0.3 x V
IN
V
IL(SHDN)
SHDN Input Low Voltage
FPLL = GND or IN µA0.01 1I
IN(FPLL)
FPLL Input Current
µA0.01 1I
IN(SHDN)
SHDN Input Current
V0.7 x V
IN
V
IH(SHDN)
SHDN Input High Voltage
I
SINK
= 2mA V0.05 0.4V
OL(RDY)
RDY Output Low Voltage
V
RDY
= 5.5V µA0.01 1I
LKG(RDYOH)
RDY Output High Leakage
FPLL = GND
FPLL = REF
FPLL = IN
Note 1: DC-DC 1 operates at one-half of the VCOfrequency (fC / 2).
BACKPLANE DRIVER
PLL
LOGIC SIGNALS
MAX1664
Active-Matrix Liquid Crystal Display
(AMLCD) Supply
4 _______________________________________________________________________________________
__________________________________________Typical Operating Characteristics
(f
BPCLK
= 22.5kHz, FPLL = GND, L1 = 3.3µH, L2 = 4.7µH, TA= +25°C, unless otherwise noted.)
100
0
1 10 100 1000
DC-DC 1 EFFICIENCY vs. LOAD CURRENT
(V
OUT1
= +5V)
20
MAX1664 TOC01
LOAD CURRENT (mA)
EFFICIENCY (%)
40
60
80
90
10
30
50
70
VIN = 3V
VIN = 4.5V
100
0
1 10 100
DC-DC 2 EFFICIENCY vs. LOAD CURRENT
(V
OUT2-
= -5V)
20
10
MAX1664 TOC02
LOAD CURRENT (mA)
EFFICIENCY (%)
40
30
60
70
50
80
90
V
OUT2+
UNLOADED
VIN = 5V
VIN = 3.3V
100
0
1 10 100
DC-DC 2 EFFICIENCY vs. LOAD CURRENT
(V
OUT2+
= +15V)
20
10
MAX1664 TOC03
LOAD CURRENT (mA)
EFFICIENCY (%)
40
30
60
70
50
80
90
V
OUT2-
UNLOADED
VIN = 5V
VIN = 3.3V
10mV/div
V
OUT1
RIPPLE
MAX1664 TOC04
I
OUT1
= 250mA, L = 3.3µH
500ns/div
V
OUT2
100mV/
div
V
OUT2+
RIPPLE
MAX1664 TOC05
2µs/div
V
OUT2+
= 15V, VIN = 3.3V, I
LOAD
= 9mA,
C
OUT2
= 0.22µF, AC COUPLED
V
OUT2-
50mV/
div
V
OUT2-
RIPPLE
MAX1664 TOC06
5µs/div
V
OUT2-
= -5V, VIN = 3.3V, I
LOAD
= 5mA,
C
OUT2-
= 0.47µF, AC COUPLED
MAX1664
Active-Matrix Liquid Crystal Display
(AMLCD) Supply
_______________________________________________________________________________________
5
Typical Operating Characteristics (continued)
(f
BPCLK
= 22.5kHz, FPLL = GND, L1 = 3.3µH, L2 = 4.7µH, TA= +25°C, unless otherwise noted.)
V
OUT2-
= -5V, I
LOAD
= 5mA, C
OUT2-
= 0.47µF
A: V
OUT2-
, 200mV/div, AC COUPLED
B: V
IN
, 3V to 4V
V
OUT2-
LINE-TRANSIENT RESPONSE
A
B
MAX1664 TOC09
200mV/
div
500mV/
div
2ms/div
V
OUT1
= 5V, VIN = 3.3V, C
OUT1
= 20µF
A: V
OUT1
, 50mV/div, AC COUPLED
B: I
OUT1
, 25mA TO 225mA, 100mA/div
V
OUT1
LOAD-TRANSIENT RESPONSE
A
B
MAX1664 TOC10
50mV/
div
100mA/
div
2ms/div
0
400
200
800
600
1200
1000
1400
0 20 3010 40 50 60 70 80 90
INTERNAL FET ON-RESISTANCE
vs. TEMPERATURE
MAX1664 TOC 11
TEMPERATURE (°C)
INTERNAL FET ON-RESISTANCE (mΩ)
LX2N
LX2P
BPDRV N-CHANNEL
LX1
BPDRV P-CHANNEL
300
0
0.001 0.01 0.1 1
BPDRV RISE AND FALL TIME
vs. LOAD CAPACITANCE
MAX1664 TOC12
LOAD CAPACITANCE (µF)
RISE/FALL TIME (ns)
100
200
250
50
150
C
LOAD
FROM
BPDRV TO GND
RISE TIME
FALL TIME
V
OUT1
= 5V, I
LOAD
= 250mA, C
OUT1
= 20µF
A: V
OUT1
, 50mV/div, AC COUPLED
B: V
IN
, 3V to 4V
V
OUT1
LINE-TRANSIENT RESPONSE
A 50mV/
div
500mV/
div
2ms/div
B
MAX1664 TOC07
V
OUT2+
= 15V, I
LOAD
= 5mA, C
OUT2+
= 0.22µF
A: V
OUT2+
, 200mV/div, AC COUPLED
B: V
IN
, 3V to 4V
V
OUT2+
LINE-TRANSIENT RESPONSE
A
B
MAX1664 TOC08
200mV/
div
500mV/
div
2ms/div
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