MAX17010ETL+ [MAXIM]

Internal-Switch Boost Regulator with Integrated High-Voltage Level Shifter and Op Amp; 内置开关的boost调节器,集成高压电平转换器和运算放大器
MAX17010ETL+
型号: MAX17010ETL+
厂家: MAXIM INTEGRATED PRODUCTS    MAXIM INTEGRATED PRODUCTS
描述:

Internal-Switch Boost Regulator with Integrated High-Voltage Level Shifter and Op Amp
内置开关的boost调节器,集成高压电平转换器和运算放大器

转换器 电平转换器 稳压器 开关式稳压器或控制器 调节器 电源电路 开关式控制器 运算放大器 信息通信管理
文件: 总17页 (文件大小:284K)
中文:  中文翻译
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19-0709; Rev 0; 3ꢂ07  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
MAX710  
General Description  
Features  
o 1.8 V to 5.5V IN Supply Voltage Range  
The MAX17010 contains a high-performance step-up  
switching regulator, a high-speed operational amplifier  
(op amp), and a high-voltage level-shifting scan driver.  
The device is optimized for thin-film transistor (TFT) liquid-  
crystal display (LCD) applications.  
o 3mA SUP Quiescent Current (Switching)  
o 1.2MHz Current-Mode Step-Up Regulator  
Fast Transient Response  
High-Accuracy Output Voltage (1.0%)  
Built-In 20V, 1.9A, 200mΩ MOSFET  
High Efficiency (> 85%)  
The step-up DC-DC converter provides the regulated  
supply voltage for the panel-source driver ICs. The con-  
verter is a 1.2MHz current-mode regulator with an inte-  
grated 20V n-channel power MOSFET. The high  
switching frequency allows the use of ultra-small induc-  
tors and ceramic capacitors. The current-mode control  
architecture provides fast transient response to pulsed  
loads. The step-up regulator features undervoltage  
lockout (UVLO), soft-start, and internal current limit. The  
high-current op amp is designed to drive the LCD  
backplane (VCOM). The amplifier features high output  
current ( 1ꢀ0mA), fast slew rate (ꢁꢀVꢂ/s), wide band-  
width (20MHz), and rail-to-rail inputs and outputs.  
Digital Soft-Start  
o High-Speed Op Amp  
150mA Output Current  
45V/µs Slew Rate  
20MHz, -3dB Bandwidth  
o High-Voltage Level-Shifting Scan Drivers  
Logic-Level Inputs  
+30V to -10V Output Rails  
o Thermal-Overload Protection  
o 40-Pin, 5mm x 5mm, Thin QFN Package  
The high-voltage, level-shifting scan driver is designed  
to work with panels that incorporate row drivers on the  
panel glass. Its eight outputs swing from +30V (max) to  
-10V and can swiftly drive capacitive loads.  
Minimal Operating Circuit  
V
V
IN  
MAIN  
The MAX17010 is available in a ꢁ0-pin thin QFN pack-  
age with a maximum thickness of 0.8mm for ultra-thin  
LCD panels. The device operates over the -ꢁ0°C to  
+8ꢀ°C temperature range.  
LX  
SHDN  
IN  
FB  
.
Applications  
Notebook Computer Displays  
LCD Monitor Panels  
PGND  
SUP  
COMP  
Ordering Information  
AGND  
VL  
POS  
PART  
TEMP RANGE  
PIN-PACKAGE  
ꢁ0 Thin QFN-EP*  
(ꢀmm x ꢀmm)  
MAX17010ETL+  
-ꢁ0°C to +8ꢀ°C  
MAX17010  
NEG  
+Denotes a lead-free package.  
*EP = Exposed paddle.  
TO VCOM  
BACKPLANE  
GON1  
GON2  
VCOM  
BGND  
A1  
A2  
A3  
A4  
A5  
A6  
A7  
A8  
Y1  
Y2  
Y3  
Y4  
Y5  
Y6  
Y7  
Y8  
EP  
Pin Configuration appears at end of data sheet.  
________________________________________________________________ Maxim Integrated Products  
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at  
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
ABSOLUTE MAXIMUM RATINGS  
IN, SHDN to GND..................................................-0.3V to +7.ꢀV  
VL to AGND...........................................................-0.3V to +6.0V  
COMP, FB to GND ........................................-0.3V to (VL + 0.3V)  
Y1–Y6 to AGND.......................(V  
Y7, Y8 to AGND.......................(V  
LX, PGND RMS Current Rating.............................................2.ꢁA  
- 0.3V) to (V  
- 0.3V) to (V  
+ 0.3V)  
+ 0.3V)  
GOFF  
GOFF  
GON1  
GON2  
Continuous Power Dissipation (T = +70°C) NiPd Lead Frame  
VCOM, NEG, POS to BGND .....................-0.3V to (V  
+ 0.3V)  
A
SUP  
with Nonconductive Epoxy  
LX to GND ..............................................................-0.3V to +20V  
SUP to GND............................................................-0.3V to +20V  
A_ to AGND............................................................-0.3V to +20V  
A_ Input Current..................................................................20mA  
PGND, BGND to AGND.........................................-0.3V to +0.3V  
GON1, GON2 to AGND..........................................-0.3V to +32V  
GOFF to AGND......................................................-12V to + 0.3V  
ꢁ0-Pin, ꢀmm x ꢀmm, Thin QFN (derate 3ꢀ.7mWꢂ°C above  
+70°C)........................................................................28ꢀ7mW  
Operating Temperature Range ...........................-ꢁ0°C to +8ꢀ°C  
Junction Temperature......................................................+1ꢀ0°C  
Storage Temperature Range.............................-6ꢀ°C to +1ꢀ0°C  
Lead Temperature (soldering, 10s) .................................+300°C  
MAX710  
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 = V  
= +3V, Circuit of Figure 1, SUP = 8.ꢀV, V  
= V  
= 30V, V  
= -10V, V  
= V  
= ꢁV, T = 0°C to +85°C.  
A
NEG  
GON1  
GON2  
GOFF  
IN  
SHDN  
POS  
Typical values are at T = +2ꢀ°C, unless otherwise noted.)  
A
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX  
ꢀ.ꢀ  
UNITS  
V
IN Input-Voltage Range  
1.8  
IN Quiescent Current  
IN Undervoltage Lockout  
Thermal Shutdown  
V
= 3V, V = 1.ꢀV, not switching  
0.0ꢀ  
1.30  
160  
0.10  
mA  
IN  
FB  
IN rising; typical hysteresis 100mV; LX remains off below  
this level  
Rising edge, 1ꢀoC hysteresis  
1.7ꢀ  
V
oC  
BOOTSTRAP LINEAR REGULATOR (VL)  
VL Output Voltage  
3.8  
2.ꢁ  
10  
ꢁ.0  
2.7  
ꢁ.2  
3.0  
V
V
VL Undervoltage Lockout  
VL Maximum Output Current  
MAIN DC-DC CONVERTER  
VL rising, 200mV hysteresis (typ)  
V
= 1V  
mA  
FB  
V
V
= 1.ꢀV, no load  
= 1.1V, no load  
1.ꢀ  
3.ꢀ  
2.ꢀ  
ꢁ.ꢀ  
FB  
FB  
SUP Supply Current  
mA  
Operating Frequency  
Oscillator Maximum Duty Cycle  
FB Regulation Voltage  
FB Load Regulation  
990  
88  
1170  
92  
13ꢀ0  
96  
kHz  
%
FB = COMP  
0 < I < 200mA, transient only  
1.222  
1.23ꢀ  
-1  
1.2ꢁ8  
V
%
MAIN  
FB Line Regulation  
V
V
= 1.8V to ꢀ.ꢀV  
= 1.3V  
0
%ꢂV  
nA  
/S  
VꢂV  
V
IN  
FB Input Bias Current  
FB Transconductance  
FB Voltage Gain  
ꢀ0  
7ꢀ  
12ꢀ  
160  
2ꢁ00  
1.00  
100  
200  
0.01  
1.9  
200  
280  
FB  
ΔI = ꢀ/A at COMP  
FB to COMP  
FB Fault-Timer Trip Threshold  
FB Undervoltage Switching Inhibit  
LX On-Resistance  
Falling edge  
0.96  
ꢀ0  
1.0ꢁ  
1ꢀ0  
330  
20  
mV  
mΩ  
/A  
A
I
= 200mA  
LX  
LX Leakage Current  
V
= 13V  
LX  
LX Current Limit  
6ꢀ% duty cycle  
1.6  
2.2  
Current-Sense Transresistance  
Soft-Start Period  
0.2ꢀ  
0.ꢁ2  
3
0.ꢀꢀ  
VꢂA  
ms  
2
_______________________________________________________________________________________  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
MAX710  
ELECTRICAL CHARACTERISTICS (continued)  
(V = V  
= +3V, Circuit of Figure 1, SUP = 8.ꢀV, V  
= V  
= 30V, V  
= -10V, V  
= V  
= ꢁV, T = 0°C to +85°C.  
A
NEG  
GON1  
GON2  
GOFF  
IN  
SHDN  
POS  
Typical values are at T = +2ꢀ°C, unless otherwise noted.)  
A
PARAMETER  
CONTROL INPUTS  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
SHDN Input-Low Voltage  
0.6  
V
V
1.8V V 3.0V  
1.8  
2.0  
-1  
IN  
SHDN Input-High Voltage  
3.0V V ꢀ.ꢀV  
IN  
Maximum SHDN Input Current  
OP AMP  
+1  
/A  
SUP Supply Range  
18  
19.9  
1.ꢁ  
V
V
SUP Overvoltage Threshold  
SUP Undervoltage Threshold  
Input Offset Voltage  
Input Bias Current  
(Note 1)  
(Note 2)  
18.1  
19.0  
V
V
V
, V  
= V  
= V  
ꢂ 2  
12  
mV  
nA  
NEG POS  
SUP  
SUP  
, V  
ꢂ 2  
-ꢀ0  
0
+ꢀ0  
NEG POS  
Input Common-Mode Voltage  
Range  
V
V
SUP  
V
- 100  
V
SUP  
SUP  
- ꢀ0  
VCOM Output-Voltage Swing High  
I
I
= ꢀmA  
mV  
VCOM  
VCOM  
VCOM Output-Voltage Swing Low  
VCOM Output Current High  
VCOM Output Current Low  
Slew Rate  
= -ꢀmA  
ꢀ0  
+7ꢀ  
-7ꢀ  
ꢁ0  
100  
mV  
mA  
V
V
= V  
- 1V  
SUP  
VCOM  
VCOM  
= 1V  
mA  
Vꢂ/s  
MHz  
-3dB Bandwidth  
20  
Short to V  
Short to V  
ꢂ 2, sourcing  
ꢂ 2, sinking  
ꢀ0  
ꢀ0  
1ꢀ0  
1ꢀ0  
SUP  
SUP  
VCOM Short-Circuit Current  
mA  
HIGH-VOLTAGE SCAN DRIVER  
GON1 Input-Voltage Range  
GON2 Input-Voltage Range  
GOFF Input-Voltage Range  
GOFF Supply Current  
12  
12  
30  
30  
V
V
-10  
-ꢀ  
V
A1–A8 = AGND, no load  
A1–A8 = AGND, no load  
A1–A8 = AGND, no load  
7ꢀ  
30  
12ꢀ  
60  
/A  
/A  
/A  
GON1 Supply Current  
GON2 Supply Current  
10  
20  
V
+ 0.3  
V
GOFF  
+ 1.0  
GOFF  
Output-Voltage Low (Y1–Y8)  
Output-Voltage High (Y1–Y6)  
Output-Voltage High (Y7–Y8)  
I
I
I
=10mA  
=10mA  
=10mA  
V
V
V
OUT  
OUT  
OUT  
V
V
GON1  
- 1.0  
GON1  
- 0.3  
V
V
GON2  
- 1.0  
GON2  
- 0.3  
Propagation Delay  
C
C
C
C
= 100pF (Note 3)  
ꢁ0  
16  
16  
80  
3ꢀ  
3ꢀ  
ns  
ns  
LOAD  
LOAD  
LOAD  
LOAD  
Rise Time (Y1–Y8)  
= 100pF (Note 3)  
= 100pF (Note 3)  
= 100pF (Note 3)  
Fall Time (Y1–Y8)  
ns  
Maximum Operating Frequency  
ꢀ0  
kHz  
_______________________________________________________________________________________  
3
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
ELECTRICAL CHARACTERISTICS (continued)  
(V = V  
= +3V, Circuit of Figure 1, SUP = 8.ꢀV, V  
= V  
= 30V, V  
= -10V, V  
= V  
= ꢁV, T = 0°C to +85°C.  
A
NEG  
GON1  
GON2  
GOFF  
IN  
SHDN  
POS  
Typical values are at T = +2ꢀ°C, unless otherwise noted.)  
A
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
CONTROL INPUTS  
Logic Input-Voltage Threshold  
Rising (A1–A8)  
1.2  
0.7  
1.6  
0.9  
2.0  
V
V
Logic Input-Voltage Threshold  
Falling (A1–A8)  
1.12  
MAX710  
Logic Input-Voltage Hysteresis  
0.7  
20  
V
Logic Input Bias Current (A1–A8)  
V
= 18V  
ꢁꢀ  
/A  
A1–A8  
ELECTRICAL CHARACTERISTICS  
(V = V  
= +3V, Circuit of Figure 1, SUP = 8V, V  
= V  
= 30, V  
= -10V, V  
= V  
= ꢁV, OE = 0V, T = -40°C to  
A
NEG  
GON1  
GON2  
GOFF  
IN  
SHDN  
POS  
+85°C.) (Note ꢁ)  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX  
ꢀ.ꢀ  
UNITS  
V
IN Input-Voltage Range  
IN Quiescent Current  
1.8  
V
= 3V, V = 1.ꢀV, not switching  
0.1  
mA  
IN  
FB  
IN rising; 100mV hysteresis (typ); LX remains off below  
this level  
IN Undervoltage Lockout  
1.7ꢀ  
V
BOOTSTRAP LINEAR REGULATOR (VL)  
VL Output Voltage  
3.8  
2.ꢁ  
10  
ꢁ.2  
3.0  
V
V
VL Undervoltage Lockout  
VL Maximum Output Current  
MAIN DC-DC CONVERTER  
VL rising, 200mV hysteresis (typ)  
V
= 1V  
mA  
FB  
V
V
= 1.ꢀV, no load  
= 1.1V, no load  
2.8  
ꢀ.0  
FB  
FB  
SUP Supply Current  
mA  
Operating Frequency  
990  
88  
13ꢀ0  
96  
kHz  
%
Oscillator Maximum Duty Cycle  
FB Regulation Voltage  
FB Transconductance  
FB = COMP  
1.216  
7ꢀ  
1.2ꢀꢁ  
280  
1.0ꢁ  
1ꢀ0  
330  
2.2  
V
ΔI = ꢀ/A at COMP  
Falling edge  
/S  
V
FB Fault Timer Trip Threshold  
FB Undervoltage Switching Inhibit  
LX On-Resistance  
0.96  
ꢀ0  
mV  
mΩ  
A
I
LX  
= 200mA  
LX Current Limit  
6ꢀ% duty cycle  
1.6  
OP AMP  
SUP Supply Range  
18  
19.9  
1.ꢁ  
12  
V
V
SUP Overvoltage Fault Threshold  
SUP Undervoltage Fault Threshold  
Input Offset Voltage  
(Note 1)  
(Note 2)  
18  
V
V
, V  
= V  
ꢂ 2  
SUP  
mV  
V
NEG POS  
Input Common-Mode Voltage Range  
0
V
SUP  
V
- 100  
SUP  
VCOM Output-Voltage Swing High  
VCOM Output-Voltage Swing Low  
VCOM Short-Circuit Current  
I
I
= ꢀmA  
mV  
mV  
mA  
VCOM  
= -ꢀmA  
100  
VCOM  
Short to V  
Short to V  
ꢂ 2, sourcing  
ꢂ 2 , sinking  
ꢀ0  
ꢀ0  
SUP  
SUP  
4
_______________________________________________________________________________________  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
MAX710  
ELECTRICAL CHARACTERISTICS (continued)  
(V = V  
= +3V, Circuit of Figure 1, SUP = 8V, V  
= V  
= 30, V  
= -10V, V  
= V  
= ꢁV, OE = 0V, T = -40°C to  
A
NEG  
GON1  
GON2  
GOFF  
IN  
SHDN  
POS  
+85°C.) (Note ꢁ)  
PARAMETER  
CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
HIGH-VOLTAGE SCAN DRIVER  
GON1 Input-Voltage Range  
GON2 Input-Voltage Range  
GOFF Input-Voltage Range  
GOFF Supply Current  
12  
12  
30  
30  
-ꢀ  
V
V
-10  
V
A1–A8 = AGND, no load  
A1–A8 = AGND, no load  
A1–A8 = AGND, no load  
12ꢀ  
60  
20  
/A  
/A  
/A  
GON1 Supply Current  
GON2 Supply Current  
V
GOFF  
+ 1  
Output-Voltage Low (Y1–Y8)  
Output-Voltage High (Y1–Y6)  
I
I
I
=10mA  
=10mA  
=10mA  
V
V
V
OUT  
OUT  
OUT  
V
V
GON1  
- 1  
GON2  
- 1  
Output-Voltage High (Y7–Y8)  
CONTROL INPUTS  
Logic Input-Voltage Threshold  
Rising (A1–A8)  
1.2  
2.0  
V
Logic Input-Voltage Threshold  
Falling (A1–A8)  
0.67  
1.12  
ꢀꢀ  
V
Logic Input Bias Current (A1–A8)  
V
= 18V  
/A  
A1–A8  
Note 1: Inhibits boost switching if SUP exceeds the overvoltage threshold. Switching resumes when SUP drops below the threshold.  
Note 2: Boost switching is not enabled until SUP is above undervoltage threshold.  
Note 3: Guaranteed by design, not production tested.  
Note 4: -ꢁ0°C specifications are guaranteed by design, not production tested.  
_______________________________________________________________________________________  
5
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
Typical Operating Characteristics  
(Circuit of Figure 1, V = 3V, V  
= 8.ꢀV, T = +2ꢀ°C, unless otherwise noted.)  
A
IN  
MAIN  
STEP-UP CONVERTER  
LOAD REGULATION  
STEP-UP CONVERTER EFFICIENCY  
VL LOAD REGULATION  
100  
90  
80  
70  
60  
50  
40  
30  
20  
10  
0
0
0.2  
0
V
= 5.0V  
IN  
V
= 5.0V  
IN  
-0.05  
-0.10  
V
= 3.3V  
IN  
-0.2  
MAX710  
-0.15  
-0.20  
-0.25  
-0.30  
-0.35  
-0.40  
-0.4  
-0.6  
V
= 3.3V  
IN  
V
= 1.8V  
IN  
V
= 1.8V  
IN  
-0.8  
-1.0  
V
= 3.3V  
IN  
1
10  
100  
1000  
0.01  
0.1  
1
10  
1
10  
100  
1000  
10,000  
LOAD CURRENT (mA)  
LOAD CURRENT (mA)  
LOAD CURRENT (mA)  
STEP-UP CONVERTER LINE REGULATION  
UNDER DIFFERENT LOADS  
IN SUPPLY QUIESCENT CURRENT  
vs. IN SUPPLY VOLTAGE  
INPUT SUPPLY CURRENT  
vs. TEMPERATURE  
80  
70  
60  
50  
70  
60  
0.4  
V
= 5V  
IN  
NO LOAD  
0.2  
0
50  
40  
NO LOAD  
-0.2  
0.1A LOAD  
40  
30  
20  
10  
V
= 3.3V  
IN  
30  
20  
10  
0
-0.4  
-0.6  
-0.8  
-1.0  
0.3A LOAD  
0.2A LOAD  
0.2A LOAD  
NO LOAD ON V  
MAIN  
0
1.8 2.3 2.8 3.3 3.8 4.3 4.8 5.3 5.8  
INPUT VOLTAGE (V)  
1.6 2.1 2.6 3.1 3.6 4.1 4.6 5.1 5.6  
SUPPLY VOLTAGE (V)  
-60 -40 -20  
0
20 40 60 80 100  
TEMPERATURE (°C)  
STEP-UP CONVERTER SWITCHING  
FREQUENCY vs. INPUT VOLTAGE  
STEP-UP CONVERTER SOFT-START  
WITH HEAVY LOAD  
MAX17010 toc08  
1.20  
1.19  
1.18  
1.17  
1.16  
1.15  
1.14  
1.13  
1.12  
100mA LOAD  
LX  
5V/div  
0V  
0V  
V
MAIN  
5V/div  
I
L
500mA/div  
SHDN  
CONTROL  
5V/div  
0mA  
0V  
1.11  
1.10  
1.6 2.1 2.6 3.1 3.6 4.1 4.6 5.1 5.6  
INPUT VOLTAGE (V)  
2ms/div  
6
_______________________________________________________________________________________  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
MAX710  
Typical Operating Characteristics (continued)  
(Circuit of Figure 1, V = 3V, V  
= 8.ꢀV, T = +2ꢀ°C, unless otherwise noted.)  
A
IN  
MAIN  
STEP-UP CONVERTER LOAD-TRANSIENT  
STEP-UP CONVERTER PULSED LOAD-  
RESPONSE (30mA TO 300mA)  
TRANSIENT RESPONSE (30mA TO 1A)  
MAX17010 toc09  
MAX17010 toc10  
V
LX  
V
LX  
10V/div  
10V/div  
0V  
0A  
0V  
0A  
I
L
I
L
1A/div  
1A/div  
V
V
MAIN  
AC-COUPLED  
200mV/div  
MAIN  
AC-COUPLED  
200mV/div  
LOAD CURRENT  
200mA/div  
LOAD CURRENT  
1A/div  
0mA  
0A  
100μs/div  
10μs/div  
STEP-UP CONVERTER TIMER DELAY  
POWER-UP SEQUENCE OF ALL  
LATCH RESPONSE TO OVERLOAD  
SUPPLY OUTPUTS  
MAX17010 toc11  
MAX17010 toc12  
V
L
5V/div  
V
0V  
0V  
LX  
V
MAIN  
10V/div  
5V/div  
0V  
V
V
GON  
MAIN  
20V/div  
5V/div  
0V  
0A  
0A  
0V  
0V  
V
COM  
5V/div  
I
L
V
IN  
2A/div  
5V/div  
0V  
V
GOFF  
10V/div  
LOAD CURRENT  
1A/div  
SHDN  
CONTROL  
5V/div  
0V  
10ms/div  
2ms/div  
SUP SUPPLY CURRENT  
vs. TEMPERATURE  
OPERATIONAL AMPLIFIER  
FREQUENCY RESPONSE  
OPERATIONAL AMPLIFIER  
POWER-SUPPLY REJECTION RATIO  
3.0  
2.5  
2.0  
10  
5
0
-10  
-20  
V
= 3.3V  
IN  
NO LOAD  
0
V
= 5.0V  
IN  
1.5  
1.0  
0.5  
-5  
-10  
-15  
-30  
-40  
-50  
100pF LOAD  
10k  
A
V
= 1V  
V
NO LOAD ON V  
MAIN  
= 3.3V  
IN  
0
-20  
-60  
-60 -40 -20  
0
20 40 60 80 100  
100  
1k  
100k  
10  
100  
1k  
10k  
100k  
TEMPERATURE (°C)  
FREQUENCY (Hz)  
FREQUENCY (Hz)  
_______________________________________________________________________________________  
7
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
Typical Operating Characteristics (continued)  
(Circuit of Figure 1, V = 3V, V  
= 8.ꢀV, T = +2ꢀ°C, unless otherwise noted.)  
MAIN A  
IN  
OPERATIONAL AMPLIFIER RAIL-TO-RAIL  
OPERATIONAL AMPLIFIER  
OPERATIONAL AMPLIFIER  
INPUT/OUTPUT WAVEFORMS  
LOAD-TRANSIENT RESPONSE  
LARGE-SIGNAL STEP RESPONSE  
MAX17010 toc16  
MAX17010 toc17  
MAX17010 toc18  
V
VCOM  
(AC-COUPLED)  
100mV/div  
V
POS  
V
0mV  
0mA  
POS  
5V/div  
5V/div  
MAX710  
0V  
0V  
0V  
0V  
I
V
VCOM  
5V/div  
VCOM  
50mA/div  
V
VCOM  
5V/div  
10μs/div  
20μs/div  
40μs/div  
OPERATIONAL AMPLIFIER  
SCAN DRIVER INPUT/OUTPUT  
SMALL-SIGNAL STEP RESPONSE  
WAVEFORMS WITH LOGIC INPUT  
MAX17010 toc19  
MAX17010 toc20  
V
A
V
5V/div  
POS  
0V  
0V  
(AC-COUPLED)  
100mV/div  
V
Y
V
10V/div  
VCOM  
(AC-COUPLED)  
100mV/div  
40μs/div  
4μs/div  
SCAN DRIVER PROPAGATION DELAY  
SCAN DRIVER PROPAGATION DELAY  
(RISING EDGE)  
(FALLING EDGE)  
MAX17010 toc21  
MAX17010 toc22  
V
A
V
A
5V/div  
0V  
0V  
5V/div  
0V  
0V  
V
V
Y
10V/div  
Y
10V/div  
100ns/div  
100ns/div  
8
_______________________________________________________________________________________  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
MAX710  
Pin Description  
PIN  
NAME  
N.C.  
FUNCTION  
1, 2ꢁ, 30,  
31, ꢁ0  
No Connection. Not internally connected.  
2, 3  
PGND  
FB  
Power Ground. Source connection of the internal step-up regulator power switch.  
Feedback Pin. Connect external resistor-divider tap here and minimize trace area. Set V  
OUT  
according to: V  
= 1.23ꢀV (1 + R1ꢂR2) (Figure 1).  
OUT  
AGND  
GON1  
Ground  
Gate-On Supply. GON1 is the positive supply for the Y1–Y6 level-shifter circuitry. Bypass to AGND  
with a minimum 0.1/F ceramic capacitor.  
6
Gate-Off Supply. GOFF is the negative supply voltage for the Y1–Y8 high-voltage driver outputs.  
Bypass to AGND with a minimum 0.1/F ceramic capacitor.  
7
GOFF  
8–11  
12–19  
20–23  
A1–Aꢁ  
Y1–Y8  
Aꢀ–A8  
High-Voltage-Driver Logic-Level Inputs  
Level-Shifter High-Voltage Outputs  
High-Voltage-Driver Logic-Level Inputs  
Gate-On Supply. GON2 is the positive supply for the Y7 and Y8 level-shifter circuitry. Bypass to AGND  
with a minimum 0.1/F ceramic capacitor.  
2ꢀ  
26  
27  
GON2  
AGND  
COMP  
Ground. Internally connected to pin ꢀ.  
Compensation Pin for Error Amplifier. Connect a series RC from this pin to AGND. Typical values are  
100kΩ and 220pF.  
ꢁV On-Chip Regulator Output. This regulator powers internal analog circuitry for the boost and op  
amp. Bypass VL to AGND with a 0.22/F or greater ceramic capacitor.  
28  
VL  
29  
32  
33  
3ꢁ  
3ꢀ  
BGND  
SUP  
Amplifier Ground  
Op Amp and Internal VL Linear Regulator Supply Input. Bypass SUP to BGND with a 0.1/F capacitor.  
POS  
Op Amp Noninverting Input  
Op Amp Inverting Input  
Op Amp Output  
NEG  
VCOM  
Shutdown Control Input. Pull SHDN low to turn off the DC-DC converter and high-voltage drivers only  
(VL and op amp remain on).  
36  
SHDN  
37  
38, 39  
IN  
LX  
EP  
Supply Pin. Bypass to AGND with a minimum 0.1/F ceramic capacitor.  
Switching Node. Connect inductorꢂcatch diode here and minimize trace area for lowest EMI.  
Exposed Backside Paddle  
_______________________________________________________________________________________  
9
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
V
GON  
0.1μF  
0.1μF  
0.1μF  
D4  
0.1μF  
V
GOFF  
0.1μF  
0.1μF  
D2  
V
V
IN  
D3  
MAIN  
+2.7V TO +5.5V  
+8.5V/300mA  
L1  
3.6μH  
MAX710  
C1  
10μF  
6.3V  
C2  
4.7μF  
10V  
C3  
4.7μF  
10V  
R1  
200kΩ  
1%  
D1  
FB  
0Ω  
LX  
SHDN  
IN  
R2  
34kΩ  
1%  
1μF  
PGND  
SUP  
COMP  
C
220pF  
R
COMP  
COMP  
0.1μF  
R5  
100kΩ  
200kΩ  
AGND  
VL  
POS  
NEG  
0.22μF  
R6  
200kΩ  
MAX17010  
TO VCOM  
BACKPLANE  
V
GON1  
GON  
VCOM  
BGND  
GON2  
GOFF  
V
GOFF  
A1  
A2  
A3  
A4  
A5  
A6  
A7  
A8  
Y1  
Y2  
Y3  
Y4  
Y5  
Y6  
Y7  
Y8  
EP  
Figure 1. MAX17010 Typical Application Circuit  
Table 1. Component List  
Typical Application Circuit  
DESIGNATION  
DESCRIPTION  
The MAX17010 typical application circuit (Figure 1)  
generates a +8.ꢀV source-driver supply and approxi-  
mately +22V and -7V gate-driver supplies for TFT dis-  
plays. The input voltage range for the IC is from +1.8V  
to +ꢀ.ꢀV, but the Figure 1 circuit is designed to run  
from 2.7V to ꢀ.ꢀV. Table 1 lists the recommended com-  
ponents and Table 2 lists the contact information of  
component suppliers.  
10/F, 6.3V XꢀR ceramic capacitor (1206)  
TDK C3216XꢀROJ106M  
C1  
ꢁ.7/F, 10V XꢀR ceramic capacitors (1206)  
TDK C3216XꢀR1Aꢁ7ꢀM  
C2, C3  
D1  
3A, 30V Schottky diode (M-flat)  
Toshiba CMS02  
200mA, 100V, dual, ultra-fast diodes (SOT23)  
Fairchild MMBDꢁ1ꢁ8SE  
D2, D3, Dꢁ  
3.6/H, 1.8A inductor  
Sumida CMD6D11BHPNP-3R6MC  
L1  
10 ______________________________________________________________________________________  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
MAX710  
Table 2. Component Suppliers  
SUPPLIER  
PHONE  
FAX  
WEBSITE  
www.fairchildsemi.com  
www.sumida.com  
Fairchild  
ꢁ08-822-2000  
8ꢁ7-ꢀꢁꢀ-6700  
8ꢁ7-803-6100  
9ꢁ9-ꢁꢀꢀ-2000  
ꢁ08-822-2102  
8ꢁ7-ꢀꢁꢀ-6720  
8ꢁ7-390-ꢁꢁ0ꢀ  
9ꢁ9-8ꢀ9-3963  
Sumida  
TDK  
www.component.tdk.com  
www.toshiba.comꢂtaec  
Toshiba  
Note: Indicate that you are using the MAX17010 when contacting these component suppliers.  
L
D
V
IN  
V
MAIN  
IN  
SHDN  
LX  
LINEAR  
REGULATOR  
VL  
AND BOOTSTRAP  
STEP-UP  
REGULATOR  
CONTROLLER  
Y1–Y6  
GON1  
PGND  
FB  
COMP  
AGND  
A1–A6  
GON2  
SUP  
NEG  
-
TO VCOM  
A7, A8  
BACKPLANE  
VCOM  
+
GOFF  
POS  
Y7, Y8  
MAX17010  
BGND  
Figure 2. MAX17010 Functional Diagram  
and provide fast transient response to pulsed loads  
found in source drivers of TFT LCD panels. The high  
switching frequency (1.2MHz) allows the use of low-pro-  
file inductors and ceramic capacitors to minimize the  
thickness of LCD panel designs. The integrated high-effi-  
ciency MOSFET and the IC’s built-in digital soft-start  
functions reduce the number of external components  
required while controlling inrush current. The output volt-  
age can be set from ꢀV to 18V with an external resistive  
voltage-divider.  
Detailed Description  
The MAX17010 contains a high-performance step-up  
switching regulator, a high-speed op amp, and a high-  
voltage, level-shifting scan driver optimized for active-  
matrix TFT LCDs. Figure 2 shows the MAX17010  
functional diagram.  
Step-Up Regulator  
The step-up regulator employs a current-mode, fixed-fre-  
quency PWM architecture to maximize loop bandwidth  
______________________________________________________________________________________ 11  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
The regulator controls the output voltage, and the power  
delivered to the output, by modulating the duty cycle (D)  
of the internal power MOSFET in each switching cycle.  
The duty cycle of the MOSFET is approximated by:  
exceed the COMP voltage, the controller resets the flip-  
flop and turns off the MOSFET. Since the inductor cur-  
rent is continuous, a transverse potential develops  
across the inductor that turns on the diode (D1). The  
voltage across the inductor then becomes the diffe-  
rence between the output voltage and the input volt-  
age. This discharge condition forces the current  
through the inductor to ramp back down, transferring  
the energy stored in the magnetic field to the output  
capacitor and the load. The MOSFET remains off for the  
rest of the clock cycle.  
V
V  
IN  
MAIN  
V
D ≈  
MAIN  
Figure 3 shows the block diagram of the step-up regu-  
lator. An error amplifier compares the signal at FB to  
1.23ꢀV and changes the COMP output. The voltage at  
COMP determines the current trip point each time the  
internal MOSFET turns on. As the load varies, the error  
amplifier sources or sinks current to the COMP output  
accordingly, to produce the inductor peak current ne-  
cessary to service the load. To maintain stability at high  
duty cycles, a slope-compensation signal is summed  
with the current-sense signal.  
MAX710  
Undervoltage Lockout (UVLO)  
The undervoltage lockout (UVLO) circuit compares the  
input voltage at IN with the UVLO threshold (1.3V rising  
and 1.2V falling) to ensure that the input voltage is high  
enough for reliable operation. The 100mV (typ) hysteresis  
prevents supply transients from causing a restart. Once  
the input voltage exceeds the UVLO rising threshold,  
startup begins. When the input voltage falls below the  
UVLO falling threshold, the controller turns off the main  
step-up regulator and the linear regulator outputs, dis-  
ables the switch-control block, and the op amp outputs  
are high impedance.  
On the rising edge of the internal clock, the controller  
sets a flip-flop, turning on the n-channel MOSFET, and  
applying the input voltage across the inductor. The cur-  
rent through the inductor ramps up linearly, storing  
energy in its magnetic field. Once the sum of the cur-  
rent-feedback signal and the slope compensation  
LX  
CLOCK  
LOGIC AND  
DRIVER  
PGND  
CURRENT-LIMIT  
COMPARATOR  
+
SOFT-  
START  
-
I
LIMIT  
SLOPE COMP  
PWM  
COMPARATOR  
CURRENT  
SENSE  
+
-
1.2MHz  
OSCILLATOR  
-
TO FAULT LOGIC  
ERROR AMP  
+
+
1.0V  
FB  
FAULT  
COMPARATOR  
-
1.235V  
COMP  
Figure 3. Step-Up Regulator Block Diagram  
12 ______________________________________________________________________________________  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
MAX710  
Linear Regulator (VL)  
The MAX17010 includes an internal ꢁV linear regulator.  
SUP is the input of the linear regulator. The input voltage  
range is between ꢀV and 18V. The output of the linear  
regulator (VL) is set to ꢁV (typ). The regulator powers all  
the internal circuitry including the MOSFET gate driver.  
Bypass the VL pin to AGND with a 0.22/F or greater  
ceramic capacitor. SUP should be directly connected to  
the output of the step-up regulator. This feature signifi-  
cantly improves the efficiency at low input voltages.  
Op Amps  
The MAX17010 has an op amp that is typically used to  
drive the LCD backplane (VCOM) andꢂor the gamma-  
correction-divider string. The op amp features 1ꢀ0mA  
output short-circuit current, ꢁꢀVꢂ/s slew rate, and  
12MHz bandwidth. While the op amp is a rail-to-rail  
input and output design, its accuracy is significantly  
degraded for input voltages within 1V of its supply rails  
(SUP and VGND).  
Short-Circuit Current Limit  
The op amp limits short-circuit current to approximately  
1ꢀ0mA if the output is directly shorted to SUP or to  
AGND. If the short-circuit condition persists, the junction  
temperature of the IC rises until it reaches the thermal-  
shutdown threshold (+160°C typ). Once the junction  
temperature reaches the thermal-shutdown threshold, an  
internal thermal sensor immediately sets the thermal fault  
latch, shutting off all the IC’s outputs except VL. The  
device remains inactive until the input voltage is cycled.  
Bootstrapping and Soft-Start  
The MAX17010 features bootstrapping operation. In nor-  
mal operation, the internal linear regulator supplies  
power to the internal circuitry. The input of the linear reg-  
ulator (SUP) should be directly connected to the output  
of the step-up regulator. The MAX17010 is enabled when  
the input voltage at SUP is above 1.ꢁV and the fault latch  
is not set. After being enabled, the regulator starts open-  
loop switching to generate the supply voltage for the  
linear regulator. Step-up switching is inhibited if the step-  
Driving Pure Capacitive Load  
The op amp is typically used to drive the LCD back-  
plane (VCOM) or the gamma-correction-divider string.  
The LCD backplane consists of a distributed series  
capacitance and resistance, a load that can be easily  
driven by the op amp. However, if the op amp is used  
in an application with a pure capacitive load, steps  
must be taken to ensure stable operation.  
up output voltage (V  
) exceeds the voltage on the  
MAIN  
SUP input. The internal reference block turns on when the  
VL voltage exceeds 2.7V (typ). When the reference volt-  
age reaches regulation, the PWM controller and the cur-  
rent-limit circuit are enabled and the step-up regulator  
enters soft-start. During soft-start, the main step-up regu-  
lator directly limits the peak inductor current, allowing  
from zero up to the full current-limit value in 128 equal  
current steps. The maximum load current is available  
after the output voltage reaches regulation (which ter-  
minates soft-start), or after the soft-start timer expires in  
approximately 3ms. The soft-start routine minimizes the  
inrush current and voltage overshoot, and ensures a  
well-defined startup behavior.  
As the op amp’s capacitive load increases, the amplifier’s  
bandwidth decreases and the gain peaking increases. A  
Ω to ꢀ0Ω small resistor placed between VCOM and the  
capacitive load reduces peaking but also reduces the  
gain. An alternative method of reducing peaking is to  
place a series RC network (snubber) in parallel with the  
capacitive load. The RC network does not continuously  
load the output or reduce the gain.  
Fault Protection  
During steady-state operation, the MAX17010 monitors  
the FB voltage. If the FB voltage does not exceed 1V  
(typ), the MAX17010 activates an internal fault timer. If  
there is a continuous fault for the fault-timer duration,  
the MAX17010 sets the fault latch, shutting down all the  
outputs except VL. Once the fault condition is removed,  
cycle the input voltage to clear the fault latch and reac-  
tivate the device. The fault-detection circuit is disabled  
during the soft-start time.  
High-Voltage Level-Shifting Scan Driver  
The MAX17010 includes eight logic-level to high-volt-  
age level-shifting buffers, which can buffer eight logic  
inputs (A1–A8) and shift them to a desired level (Y1–Y8)  
to drive TFT-LCD row logic. The driver outputs, Y1–Y8,  
swing between their power-supply rails, according to  
the input-logic level on A1–A8. The driver output is  
GOFF when its respective input is logic low, and GON_  
when its respective input is logic high. These eight dri-  
ver channels are grouped for different high-level sup-  
plies. A1–A6 are supplied from GON1, and A7 and A8  
are supplied from GON2. GON1 and GON2 can be tied  
together to make A1–A8 use identical supplies.  
The MAX17010 monitors the SUP voltage for undervolt-  
age and overvoltage conditions. If the SUP voltage is  
below 1.ꢁV (typ) or above 19V (typ), the MAX17010 dis-  
ables the gate driver of the step-up regulator and pre-  
vents the internal MOSFET from switching. The SUP  
undervoltage and overvoltage conditions do not set the  
fault latch.  
______________________________________________________________________________________ 13  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
The high-voltage, level-shifting scan drivers are  
designed to drive the TFT panels with row-drivers inte-  
grated on the panel glass. Its eight outputs swing from  
+30V (max) to -6.3V (min) and can swiftly drive capaci-  
tive loads. The typical propagation delays are ꢁ0ns,  
with fast 16ns rise-and-fall times. The buffers can oper-  
ate at frequencies up to ꢀ0kHz.  
and ratio of inductor resistance to other power-path  
resistances, the best LIR can shift up or down. If the  
inductor resistance is relatively high, more ripple can  
be accepted to reduce the number of turns required  
and increase the wire diameter. If the inductor resis-  
tance is relatively low, increasing inductance to lower  
the peak current can decrease losses throughout the  
power path. If extremely thin high-resistance inductors  
are used, as is common for LCD panel applications, the  
best LIR can increase to between 0.ꢀ and 1.0.  
Thermal-Overload Protection  
The thermal-overload protection prevents excessive  
power dissipation from overheating the device. When  
MAX710  
Once a physical inductor is chosen, higher and lower  
values of the inductor should be evaluated for efficiency  
improvements in typical operating regions.  
the junction temperature exceeds T = +160°C, a ther-  
J
mal sensor immediately activates the fault protection,  
which shuts down all outputs except VL, allowing the  
device to cool down. Once the device cools down by  
approximately 1ꢀ°C, cycle the input voltage (below the  
UVLO-falling threshold) to clear the fault latch and  
reactivate the device.  
Calculate the approximate inductor value using the typi-  
cal input voltage (V ), the maximum output current  
IN  
(I  
), the expected efficiency (η  
) taken from  
MAIN(MAX)  
TYP  
an appropriate curve in the Typical Operating  
Characteristics, and an estimate of LIR based on the  
The thermal-overload protection protects the controller in  
the event of fault conditions. For continuous operation,  
do not exceed the absolute maximum junction tempera-  
above discussion:  
2
V  
V
MAIN  
V  
× f  
η
TYP  
LIR  
IN  
IN  
L =  
ture rating of T = +1ꢀ0°C.  
J
V
I
MAIN MAIN(MAX) OSC ⎠  
Design Procedure  
Main Step-Up Regulator  
Choose an available inductor value from an appropriate  
inductor family. Calculate the maximum DC input cur-  
rent at the minimum input voltage V  
using con-  
IN(MIN)  
Inductor Selection  
servation of energy and the expected efficiency at that  
operating point (η ) taken from an appropriate curve  
The minimum inductance value, peak current rating, and  
series resistance are factors to consider when selecting  
the inductor. These factors influence the converter’s effi-  
ciency, maximum output-load capability, transient  
response time, and output-voltage ripple. Physical size  
and cost are also important factors to be considered.  
MIN  
in the Typical Operating Characteristics:  
I
× V  
MAIN(MAX)  
MAIN  
I
=
IN(DC,MAX)  
V
× η  
MIN  
IN(MIN)  
Calculate the ripple current at that operating point and  
the peak current required for the inductor:  
The maximum output current, input voltage, output volt-  
age, and switching frequency determine the inductor  
value. Very high inductance values minimize the current  
ripple and therefore reduce the peak current, which  
decreases core losses in the inductor and I2R losses in  
the entire power path. However, large inductor values  
also require more energy storage and more turns of wire,  
which increase physical size and can increase I2R losses  
in the inductor. Low inductance values decrease the  
physical size but increase the current ripple and peak  
current. Finding the best inductor involves choosing the  
best compromise between circuit efficiency, inductor  
size, and cost.  
V
× V  
V  
(
)
IN(MIN)  
MAIN  
IN(MIN)  
I
=
RIPPLE  
L × V  
× f  
MAIN OSC  
I
RIPPLE  
I
=I  
+
PEAK IN(DC,MAX)  
2
The inductor’s saturation current rating and the  
MAX17010’s LX current limit (I ) should exceed I  
LIM  
PEAK  
and the inductor’s DC current rating should exceed  
I
. For good efficiency, choose an inductor  
IN(DC,MAX)  
with less than 0.1Ω series resistance.  
Considering the Typical Operating Circuit, the maximum  
The equations used here include a constant (LIR),  
which is the ratio of the inductor peak-to-peak ripple  
current to the average DC inductor current at the full-  
load current. The best trade-off between inductor size  
and circuit efficiency for step-up regulators generally  
has an LIR between 0.3 and 0.ꢀ. However, depending  
on the AC characteristics of the inductor core material  
load current (I  
) is 300mA, with an 8.ꢀV output  
MAIN(MAX)  
and a typical input voltage of 3V. Choosing an LIR of 0.ꢁꢀ  
and estimating efficiency of 8ꢀ% at this operating point:  
2
3V  
8.ꢀV  
8.ꢀV 3V  
0.3A ×1.2MHz 0.ꢀ  
0.8ꢀ  
⎞ ⎛  
⎞⎛  
⎟⎜  
⎠⎝  
L =  
3.6μH  
⎟ ⎜  
⎠ ⎝  
14 ______________________________________________________________________________________  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
MAX710  
Using the circuit’s minimum input voltage (2.2V) and  
estimating efficiency of 80% at that operating point:  
Rectifier Diode  
The MAX17010’s high switching frequency demands a  
high-speed rectifier. Schottky diodes are recommended  
for most applications because of their fast recovery time  
and low forward voltage. In general, a 2A Schottky  
diode complements the internal MOSFET well.  
0.3A × 8.ꢀV  
2.2V × 0.8  
I
=
1.ꢁꢀA  
IN(DC,MAX)  
The ripple current and the peak current are:  
Output Voltage Selection  
The output voltage of the main step-up regulator is  
adjusted by connecting a resistive voltage-divider from  
2.2V × 8.ꢀV 2.2V  
(
)
0.38A  
I
=
RIPPLE  
3.6μH× 8.ꢀV ×1.2MHz  
the output (V  
) to AGND with the center tap con-  
MAIN  
nected to FB (see Figure 1). Select R2 in the 10kΩ to  
ꢀ0kΩ range. Calculate R1 with the following equation:  
0.38A  
2
I
=1.ꢁꢀA +  
1.6ꢁA  
PEAK  
V  
MAIN  
R1=R2×  
1  
Output Capacitor Selection  
V
REF  
The total output-voltage ripple has two components: the  
capacitive ripple caused by the charging and dis-  
charging of the output capacitance, and the ohmic rip-  
ple due to the capacitor’s equivalent series resistance  
(ESR):  
where V  
, the step-up regulator’s feedback set point,  
REF  
is 1.23ꢀV. Place R1 and R2 close to the IC.  
Loop Compensation  
Choose R  
to set the high-frequency integrator  
COMP  
V
= V  
+ V  
RIPPLE  
RIPPLE(C) RIPPLE(ESR)  
gain for fast transient response. Choose C  
the integrator zero to maintain loop stability.  
to set  
COMP  
I
C
V  
V  
IN  
MAIN  
MAIN  
V
RIPPLE(C)  
For low-ESR output capacitors, use the following equa-  
tions to obtain stable performance and good transient  
response:  
V
f
OUT  
MAIN OSC  
and:  
1000× V × V  
×C  
OUT  
V
I  
R
IN  
OUT  
RIPPLE(ESR) PEAK ESR(COUT)  
R
COMP  
L ×I  
MAIN(MAX)  
where I  
is the peak inductor current (see the  
PEAK  
Inductor Selection section). For ceramic capacitors, the  
output-voltage ripple is typically dominated by  
RIPPLE(C)  
V
×C  
OUT  
OUT  
C
COMP  
10×I  
×R  
COMP  
MAIN(MAX)  
V
. The voltage rating and temperature charac-  
teristics of the output capacitor must also be considered.  
To further optimize transient response, vary R  
in  
COMP  
20% steps and C  
in ꢀ0% steps, while observing  
COMP  
Input Capacitor Selection  
The input capacitor (C ) reduces the current peaks  
IN  
transient response waveforms.  
drawn from the input supply and reduces noise injec-  
tion into the IC. A 10/F ceramic capacitor is used in the  
Typical Applications Circuit (Figure 1) because of the  
high source impedance seen in typical lab setups.  
Actual applications usually have much lower source  
impedance since the step-up regulator often runs  
directly from the output of another regulated supply.  
Applications Information  
Power Dissipation  
An IC’s maximum power dissipation depends on the  
thermal resistance from the die to the ambient environ-  
ment, and the ambient temperature. The thermal resis-  
tance depends on the IC package, PCB copper area,  
other thermal mass, and airflow.  
Typically, C can be reduced below the values used in  
IN  
the Typical Applications Circuit. Ensure a low-noise  
The MAX17010, with its exposed backside paddle sol-  
dered to an internal ground layer in a typical multilayer  
PCB, can dissipate about 2.8W into +70°C still air.  
More PCB copper, cooler ambient air, and more airflow  
increase the possible dissipation, while less copper or  
warmer air decreases the IC’s dissipation capability.  
The major components of power dissipation are the  
power dissipated in the step-up regulator and the  
power dissipated by the op amps.  
supply at IN by using adequate C . Alternatively,  
IN  
greater voltage variation can be tolerated on C if IN is  
IN  
decoupled from C using an RC lowpass filter, as  
IN  
shown in Figure 1.  
______________________________________________________________________________________ 15  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
Step-Up Regulator  
The largest portions of power dissipation in the step-up  
regulator are the internal MOSFET, inductor, and the out-  
put diode. If the step-up regulator has 90% efficiency,  
about 3% to ꢀ% of the power is lost in the internal  
MOSFET, about 3% to ꢁ% in the inductor, and about 1%  
in the output diode. The remaining 1% to 3% is distri-  
buted among the input and output capacitors and the  
PCB traces. If the input power is about ꢀW, the power  
lost in the internal MOSFET is about 1ꢀ0mW to 2ꢀ0mW.  
2) Create a power ground island (PGND) consisting of  
the input- and output-capacitor grounds, PGND pin,  
and any charge-pump components. Connect all  
these together with short, wide traces or a small  
ground plane. Maximizing the width of the power-  
ground traces improves efficiency and reduces out-  
put-voltage ripple and noise spikes. Create an  
analog ground plane (AGND) consisting of the  
AGND pin, all the feedback-divider ground connec-  
tions, the op-amp-divider ground connections, the  
COMP capacitor ground connection, the SUP and  
VL bypass-capacitor ground connections, and the  
device’s exposed backside pad. Connect the AGND  
and PGND islands by connecting the PGND pin  
directly to the exposed backside pad. Make no other  
connections between these separate ground planes.  
MAX710  
Op Amp  
The power dissipated in the op amp depends on its out-  
put current, the output voltage, and the supply voltage:  
PD  
=I  
× V  
V  
(
)
SOURCE VCOM(SOURCE)  
SUP VOUT  
PD  
=I  
× V  
SINK VCOM(SINK) VOUT  
3) Place the feedback-voltage-divider resistors as close  
to the feedback pin as possible. The divider’s center  
trace should be kept short. Placing the resistors far  
away causes the FB trace to become an antenna  
that can pick up switching noise. Care should be  
taken to avoid running the feedback trace near LX or  
the switching nodes in the charge pumps.  
where I  
the op amp, and I  
the op amp sinks.  
is the output current sourced by  
VCOM(SINK)  
VCOM(SOURCE)  
is the output current that  
In a typical case where the supply voltage is 8.ꢀV, and  
the output voltage is ꢁV with an output source current  
of 30mA, the power dissipated is 13ꢀmV.  
ꢁ) Place the IN pin and VL pin bypass capacitors as  
close to the device as possible. The ground connec-  
tions of the IN and VL bypass capacitors should be  
connected directly to the AGND pin or the IC’s back-  
side pad with a wide trace.  
PCB Layout and Grounding  
Careful PCB layout is important for proper operation.  
Use the following guidelines for good PCB layout:  
1) Minimize the area of high-current loops by placing  
the inductor, output diode, and output capacitors  
near the input capacitors and near the LX and  
PGND pins. The high-current input loop goes from  
the positive terminal of the input capacitor to the  
inductor, to the IC’s LX pins, out of PGND, and to  
the input capacitor’s negative terminal. The high-  
current output loop is from the positive terminal of  
the input capacitor to the inductor, to the output  
diode (D1), to the positive terminal of the output  
capacitors, reconnecting between the output-  
capacitor and input-capacitor ground terminals.  
Connect these loop components with short, wide  
connections. Avoid using vias in the high-current  
paths. If vias are unavoidable, use many vias in  
parallel to reduce resistance and inductance.  
ꢀ) Minimize the length and maximize the width of the  
traces between the output capacitors and the load  
for best transient responses.  
6) Minimize the size of the LX node while keeping it  
wide and short. Keep the LX node away from the  
feedback node and analog ground. Use DC traces  
as shield if necessary.  
7) Refer to the MAX17010 evaluation kit for an example  
of proper board layout.  
16 ______________________________________________________________________________________  
Internal-Switch Boost Regulator with Integrated  
High-Voltage Level Shifter and Op Amp  
MAX710  
Pin Configuration  
Chip Information  
TRANSISTOR COUNT: 9202  
PROCESS: BiCMOS  
TOP VIEW  
30 29 28 27 26 25 24 23 22 21  
20  
31  
32  
33  
A5  
N.C.  
SUP  
POS  
19 Y8  
18 Y7  
Package Information  
For the latest package outline information, go to  
www.maxim-ic.com/packages.  
17  
16  
Y6  
Y5  
NEG 34  
35  
36  
37  
38  
39  
40  
VCOM  
SHDN  
IN  
MAX17010  
15 Y4  
14  
Y3  
13 Y2  
12  
LX  
Y1  
11 A4  
LX  
N.C.  
1
2
3
4
5
6
7
8
9
10  
THIN QFN  
(5mm x 5mm)  
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.  
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 17  
© 2007 Maxim Integrated Products  
is a registered trademark of Maxim Integrated Products, Inc.  

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