ISL78010 [INTERSIL]

Automotive Grade TFT-LCD Power Supply; 汽车级TFT- LCD电源
ISL78010
型号: ISL78010
厂家: Intersil    Intersil
描述:

Automotive Grade TFT-LCD Power Supply
汽车级TFT- LCD电源

CD
文件: 总18页 (文件大小:394K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
ISL78010  
®
Data Sheet  
May 30, 2007  
FN6501.0  
Automotive Grade TFT-LCD Power Supply  
Features  
The ISL78010 is a multiple output regulator for use in all  
TFT-LCD automotive applications. It features a single boost  
converter with an integrated 2A FET, two positive LDOs for  
• 2A current FET  
• 3V to 5V input  
• Up to 20V boost output  
• 1% regulation on boost output  
V
V
and V  
generation, and a single negative LDO for  
ON  
LOGIC  
generation. The boost converter can be programmed  
OFF  
to operate in either P-mode for optimal transient response or  
PI-mode for improved load regulation.  
• V  
-V  
-V  
-V  
or  
sequence control  
LOGIC BOOST OFF ON  
V
-V -V -V  
LOGIC OFF BOOST ON  
The ISL78010 includes fault protection for all four channels.  
Once a fault is detected on either the V  
• Programmable sequence delay  
• Fully fault protected  
, V  
or V  
BOOST ON  
OFF  
channels, the device is latched off until the input supply or  
EN is cycled. If a fault is detected on the V channel,  
LOGIC  
the device is latched off until the input supply is cycled. The  
channel is not affected by the EN function.  
• Thermal shutdown  
• Internal soft-start  
V
LOGIC  
The ISL78010 also includes an integrated start-up sequence  
for V , V , V , then V or for V , V  
• 32 Ld 5x5 TQFP packages  
• Pb-free plus anneal available (RoHS compliant)  
,
LOGIC BOOST OFF ON LOGIC OFF  
V
, and V . The latter sequence requires a single  
BOOST ON  
external transistor. The timing of the start-up sequence is set  
using an external capacitor.  
Applications  
• All Automotive LCD Displays  
The ISL78010 comes in a 32 Ld 5x5 TQFP package and is  
specified for operation over a -40°C to +105°C temperature  
range.  
Pinout  
ISL78010  
(32 LD 5X5 TQFP)  
TOP VIEW  
Ordering Information  
PART NUMBER  
(Note)  
PART  
MARKING  
PACKAGE  
(Pb-free)  
PKG.  
DWG. #  
ISL78010ANZ*  
78010ANZ 32 Ld 5x5 TQFP  
Q32.5x5  
*Add “-T” or “-TK” suffix for tape and reel. Please refer to TB347 for  
details on reel specifications.  
32 31 30 29 28 27 26 25  
NC  
1
VREF  
NC  
24  
NC  
DELB  
NC  
2
3
4
5
6
7
8
NOTE: Intersil Pb-free plus anneal products employ special Pb-free  
material sets; molding compounds/die attach materials and 100%  
matte tin plate termination finish, which are RoHS compliant and  
compatible with both SnPb and Pb-free soldering operations. Intersil  
Pb-free products are MSL classified at Pb-free peak reflow  
temperatures that meet or exceed the Pb-free requirements of  
IPC/JEDEC J STD-020.  
23  
22  
21  
20  
19  
18  
17  
PGND  
PGND  
PGND  
PGND  
NC  
LX  
NC  
DRVP  
NC  
FBN  
9 10 11 12 13 14 15 16  
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.  
1
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.  
Copyright Intersil Americas Inc. 2007. All Rights Reserved  
All other trademarks mentioned are the property of their respective owners.  
ISL78010  
Absolute Maximum Ratings (T = +25°C)  
Thermal Information  
A
V
V
V
V
V
V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24V  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36V  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -20V  
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C  
Ambient Operating Temperature . . . . . . . . . . . . . . .-40°C to +105°C  
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Curves  
Maximum Continuous Junction Temperature . . . . . . . . . . . +125°C  
Pb-free reflow profile . . . . . . . . . . . . . . . . . . . . . . . . . .see link below  
http://www.intersil.com/pbfree/Pb-FreeReflow.asp  
DELB  
DRVP  
DRVN  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5V  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24V  
DD  
LX  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5V  
DRVL  
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the  
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.  
IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests  
are at the specified temperature and are pulsed tests, therefore: T = T = T  
J
C
A
Electrical Specifications  
V
= 5V, V  
= 11V, I  
= 200mA, V  
= 15V, V  
= -5V, V  
= 2.5V, limits over -40°C to  
DD  
BOOST  
LOAD  
ON  
OFF  
LOGIC  
+105°C temperature range, unless otherwise specified.  
PARAMETER  
SUPPLY  
DESCRIPTION  
CONDITION  
MIN  
TYP  
MAX  
UNIT  
V
Supply Voltage  
3
5.5  
2.5  
V
S
I
Quiescent Current  
Enabled, LX not switching  
Disabled  
1.7  
mA  
µA  
S
750  
900  
CLOCK  
f
Oscillator Frequency  
900  
1000  
1100  
kHz  
OSC  
BOOST  
V
V
Boost Output Range  
5.5  
20  
V
V
BOOST  
FBB  
Boost Feedback Voltage  
T
= +25°C  
= +25°C  
1.192  
1.188  
1.205  
1.205  
0.9  
1.218  
1.222  
A
V
V
V
FBB Fault Trip Point  
Reference Voltage  
V
F_FBB  
REF  
T
1.19  
1.187  
85  
1.215  
1.215  
1.235  
1.238  
V
A
V
D
Maximum Duty Cycle  
Current Switch  
%
MAX  
LXMAX  
LEAK  
I
I
2.0  
A
Switch Leakage Current  
Switch ON-Resistance  
Boost Efficiency  
V
= 16V  
10  
µA  
mΩ  
%
LX  
r
320  
92  
DS(ON)  
Eff  
I(V  
ΔV  
ΔV  
See curves  
Pl mode, V  
85  
)
Feedback Input Bias Current  
Line Regulation  
= 1.35V  
50  
500  
nA  
%/V  
%
FBB  
FBB  
= 4.7nF, I = 100mA, V = 3V to 5.5V  
OUT IN  
/ΔV  
C
0.05  
3
BOOST  
IN  
INT  
INT  
/ΔI  
BOOST BOOST  
Load Regulation - “P” Mode  
C
pin strapped to V  
,
DD  
< 250mA  
50mA < I  
LOAD  
ΔV  
/ΔI  
Load Regulation - “PI” Mode  
C
= 4.7nF, 50mA < I < 250mA  
0.1  
4.7  
%
V
BOOST BOOST  
INT  
O
V
V
V
CINT Pl Mode Select Threshold  
4.8  
CINT_T  
LDO  
ON  
FBP Regulation Voltage  
I
I
= 0.2mA, T = +25°C  
A
1.176  
1.172  
0.82  
1.2  
1.2  
1.224  
1.228  
0.92  
V
V
FBP  
DRVP  
DRVP  
= 0.2mA  
falling  
V
FBP Fault Trip Point  
V
V
V
0.87  
V
F_FBP  
FBP  
I
FBP Input Bias Current  
FBP Effective Transconductance  
= 1.35V  
-250  
250  
nA  
ms  
FBP  
FBP  
GMP  
= 25V, I  
DRVP  
= 0.2mA to 2mA  
50  
DRVP  
FN6501.0  
May 30, 2007  
2
ISL78010  
Electrical Specifications  
V
= 5V, V  
= 11V, I  
LOAD  
= 200mA, V  
= 15V, V  
= -5V, V  
= 2.5V, limits over -40°C to  
DD  
BOOST  
ON  
OFF  
LOGIC  
+105°C temperature range, unless otherwise specified. (Continued)  
PARAMETER  
DESCRIPTION  
Load Regulation  
ON  
CONDITION  
MIN  
TYP  
-0.5  
4
MAX  
UNIT  
%
ΔV /ΔI(V  
ON  
)
V
I(V ) = 0mA to 20mA  
ON  
ON  
I
I
DRVP Sink Current Max  
DRVP Leakage Current  
V
V
= 1.1V, V  
= 1.5V, V  
= 25V  
= 35V  
2
mA  
µA  
DRVP  
FBP  
FBP  
DRVP  
DRVP  
0.1  
5
L_DRVP  
V
LDO  
OFF  
V
FBN Regulation Voltage  
I
I
= 0.2mA, T = +25°C  
A
0.173  
0.171  
0.38  
0.203  
0.203  
0.43  
0.233  
0.235  
0.48  
V
V
FBN  
DRVN  
DRVN  
= 0.2mA  
falling  
V
FNN Fault Trip Point  
V
V
V
V
F_FBN  
FBN  
I
FBN Input Bias Current  
FBN Effective Transconductance  
= 0.2V  
-250  
250  
nA  
mS  
%
FBN  
FBN  
GMN  
= -6V, I  
= 0.2mA to 2mA  
50  
DRVN  
DRVN  
ΔV  
/
V
Load Regulation  
I(V  
) = 0mA to 20mA  
-0.5  
OFF  
OFF  
OFF  
ΔI(V  
)
OFF  
I
I
DRVN Source Current Max  
DRVN Leakage Current  
V
V
= 0.3V, V  
= -6V  
2
4
mA  
µA  
DRVN  
L_DRVN  
FBN  
FBN  
DRVN  
= 0V, V  
= -20V  
0.1  
5
DRVN  
V
LDO  
LOGIC  
V
FBL Regulation Voltage  
I
I
= 1mA, T = +25°C  
A
1.176  
1.174  
0.82  
1.2  
1.2  
1.224  
1.226  
0.92  
V
V
FBL  
DRVL  
DRVL  
= 1mA  
falling  
V
FBL Fault Trip Point  
V
V
V
0.87  
V
F_FBL  
FBL  
I
FBL Input Bias Current  
FBL Effective Transconductance  
= 1.35V  
-500  
500  
nA  
mS  
%
FBL  
FBL  
G
= 2.5V, I  
= 1mA to 8mA  
) = 100mA to 500mA  
200  
0.5  
ML  
DRVL  
DRVL  
ΔV  
/
V
Load Regulation  
I(V  
LOGIC  
LOGIC  
LOGIC  
ΔI(V  
)
LOGIC  
I
I
DRVL Sink Current Max  
V
V
= 1.1V, V  
= 2.5V  
= 5.5V  
8
16  
mA  
µA  
DRVL  
L_DRL  
FBL  
FBL  
DRVL  
DRVL  
I
= 1.5V, V  
0.1  
5
L_DRVL  
SEQUENCING  
t
t
t
t
I
Turn On Delay  
Soft-start Time  
Delay Between A  
Delay Between V  
C
C
C
C
= 0.22µF  
= 0.22µF  
= 0.22µF  
= 0.22µF  
30  
2
ms  
ms  
ms  
ms  
µA  
mA  
ON  
DLY  
SS  
DLY  
and V  
10  
17  
50  
1.4  
DEL1  
DEL2  
DELB  
VDD  
OFF  
DLY  
and V  
ON  
OFF  
DLY  
DELB Pull-down Current  
V
V
> 0.6V  
< 0.6V  
DELB  
DELB  
FAULT DETECTION  
t
Fault Time Out  
C
= 0.22µF  
DLY  
50  
140  
15  
ms  
°C  
FAULT  
OT  
Over-temperature Threshold  
PG Pull-down Current  
I
VPG > 0.6V  
VPG < 0.6V  
µA  
mA  
PG  
1.7  
LOGIC ENABLE  
V
V
Logic High Threshold  
Logic Low Threshold  
Logic Low Bias Current  
Logic High Bias Current  
2.3  
12  
V
V
HI  
0.8  
2
LO  
I
I
0.2  
18  
µA  
µA  
LOW  
HIGH  
at V  
= 5V  
24  
EN  
FN6501.0  
May 30, 2007  
3
ISL78010  
Pin Descriptions  
PIN NAME  
PIN NUMBER  
DESCRIPTION  
1, 2, 4, 6, 8, 10, 12,  
16, 18, 23, 32  
NC  
Not connected  
3
DELB  
LX  
Open drain output for gate drive of optional V  
Drain of the internal N-Channel boost FET  
delay FET  
BOOST  
5
9
FBP  
Positive LDO voltage feedback input pin; regulates to 1.2V nominal  
Positive LDO base drive; open drain of an internal N-Channel FET  
Logic LDO base drive; open drain of an internal N-Channel FET  
Logic LDO voltage feedback input pin; regulates to 1.2V nominal  
Low noise signal ground  
7
DRVP  
DRVL  
FBL  
11  
13  
14, 27  
SGND  
DRVN  
FBN  
15  
Negative LDO base drive; open drain of an internal P-Channel FET  
Negative LDO voltage feedback input pin; regulates to 0.2V nominal  
Power ground, connected to source of internal N-Channel boost FET  
Bandgap reference output voltage; bypass with a 0.1µF to SGND  
17  
19, 20, 21, 22  
PGND  
VREF  
CINT  
24  
25  
V
integrator output; connect capacitor to SGND for PI-mode or connect to V  
for P-mode  
DD  
BOOST  
operation  
26  
28  
29  
30  
FBB  
EN  
Boost regulator voltage feedback input pin; regulates to 1.2V nominal  
Enable pin; High = Enable; Low or floating = Disable  
Positive supply  
VDD  
PG  
Push-pull gate drive of optional fault protection FET; when chip is disabled or when a fault has been  
detected, this is high  
31  
CDLY  
A capacitor connected from this pin to SGND sets the delay time for start-up sequence and sets the fault  
timeout time  
Typical Performance Curves  
T = +25°C, unless otherwise specified.  
A
100  
100  
A
= 9V  
VDD  
80  
80  
60  
40  
20  
0
A
= 12V  
VDD  
A
= 15V  
A
= 12V  
VDD  
VDD  
A
= 15V  
VDD  
60  
40  
20  
0
A
= 9V  
VDD  
0
100  
200  
(mA)  
300  
400  
0
200  
400  
(mA)  
600  
800  
I
I
OUT  
OUT  
FIGURE 2. V  
EFFICIENCY AT V = 5V (PI-MODE)  
IN  
FIGURE 1. V  
EFFICIENCY AT V = 3V (PI-MODE)  
IN  
BOOST  
BOOST  
FN6501.0  
May 30, 2007  
4
ISL78010  
Typical Performance Curves  
T
= +25°C, unless otherwise specified. (Continued)  
A
100  
100  
A
= 9V  
VDD  
80  
80  
60  
40  
20  
0
A
= 12V  
VDD  
A
= 12V  
VDD  
A
= 15V  
VDD  
A
= 15V  
VDD  
60  
40  
20  
0
A
= 9V  
VDD  
0
100  
200  
I
300  
(mA)  
400  
500  
0
200  
400  
(mA)  
600  
800  
I
OUT  
OUT  
FIGURE 4. V  
EFFICIENCY AT V = 5V (P-MODE)  
IN  
FIGURE 3. V  
EFFICIENCY AT V = 3V (P-MODE)  
IN  
BOOST  
BOOST  
0
-0.1  
-0.2  
-0.3  
-0.4  
-0.5  
-0.6  
0
-0.2  
-0.4  
-0.6  
-0.8  
A
= 9V  
VDD  
A
= 9V  
VDD  
A
= 15V  
VDD  
A
= 12V  
VDD  
A
= 15V  
VDD  
A
= 12V  
VDD  
-0.7  
0
-1.0  
0
100  
200  
(mA)  
300  
400  
200  
400  
600  
800  
I
OUT  
I
(mA)  
OUT  
FIGURE 5. V  
LOAD REGULATION AT V = 3V (PI-MODE)  
IN  
FIGURE 6. V  
LOAD REGULATION AT V = 5V (PI-MODE)  
IN  
BOOST  
BOOST  
0
-1  
-2  
-3  
-4  
-5  
0
-0.5  
-1.0  
-1.5  
-2.0  
-2.5  
-3.0  
-3.5  
-4.0  
A
= 9V  
VDD  
A
= 9V  
VDD  
A
= 15V  
VDD  
A
= 12V  
600  
VDD  
A
= 15V  
VDD  
A
= 12V  
VDD  
0
200  
400  
(mA)  
800  
0
100  
200  
300  
(mA)  
400  
500  
I
OUT  
I
OUT  
FIGURE 8. V  
LOAD REGULATION AT V = 5V (P-MODE)  
IN  
BOOST  
FIGURE 7. V  
LOAD REGULATION AT V = 3V (P-MODE)  
IN  
BOOST  
FN6501.0  
May 30, 2007  
5
ISL78010  
Typical Performance Curves  
T
= +25°C, unless otherwise specified. (Continued)  
A
0.05  
0.04  
0.03  
0.02  
0.01  
0
0
-0.5  
-1.0  
1.5  
-2.0  
-2.5  
-0.01  
-0.02  
3.0  
3.5  
4.0  
4.5  
(V)  
5.0  
5.5  
6.0  
3.0  
3.5  
4.0  
4.5  
(V)  
5.0  
5.5  
6.0  
V
V
IN  
IN  
FIGURE 9. V  
LINE REGULATION (PI-MODE)  
FIGURE 10. V  
LINE REGULATION (P-MODE)  
BOOST  
BOOST  
0
-0.2  
-0.4  
-0.6  
-0.8  
-1.0  
-1.2  
0
-0.1  
-0.2  
-0.3  
-0.4  
-0.5  
-1.4  
0
-0.6  
0
20  
40  
60  
80  
100  
20  
40  
(mA)  
60  
80  
I
(mA)  
I
OUT  
OUT  
FIGURE 12. V  
LOAD REGULATION  
FIGURE 11. V  
LOAD REGULATION  
OFF  
ON  
0
-0.2  
V
CDLY  
-0.4  
-0.6  
-0.8  
-1.0  
-1.2  
V
REF  
V
BOOST  
V
LOGIC  
C
= 220nF  
DLY  
0
100 200 300 400 500 600 700  
I
(mA)  
TIME (10ms/DIV)  
OUT  
FIGURE 14. START-UP SEQUENCE  
FIGURE 13. V  
LOAD REGULATION  
LOGIC  
FN6501.0  
May 30, 2007  
6
ISL78010  
Typical Performance Curves  
T
= +25°C, unless otherwise specified. (Continued)  
A
V
BOOST  
V
BOOST_DELAY  
V
LOGIC  
V
LOGIC  
V
OFF  
V
OFF  
C
= 220nF  
V
DLY  
ON  
C
= 220nF  
DLY  
V
ON  
TIME (10ms/DIV)  
TIME (10ms/DIV)  
FIGURE 15. START-UP SEQUENCE  
FIGURE 16. START-UP SEQUENCE  
V
V
I
= 5V  
= 13V  
V
V
I
= 5V  
= 13V  
IN  
OUT  
= 30mA  
IN  
OUT  
= 200mA  
OUT  
OUT  
TIME (400ns/DIV)  
TIME (400ns/DIV)  
FIGURE 17. LX WAVEFORM - DISCONTINUOUS MODE  
FIGURE 18. LX WAVEFORM - CONTINUOUS MODE  
JEDEC JESD51-7 HIGH EFFECTIVE THERMAL  
CONDUCTIVITY TEST BOARD  
1.8  
1.515W  
1.5  
1.2  
0.9  
0.6  
0.3  
0
0
25  
50  
75  
100  
125  
150  
AMBIENT TEMPERATURE (°C)  
FIGURE 19. PACKAGE POWER DISSIPATION vs AMBIENT  
TEMPERATURE  
FN6501.0  
May 30, 2007  
7
ISL78010  
Boost Converter  
Applications Information  
The main boost converter is a current mode PWM converter  
at a fixed frequency of 1MHz, which enables the use of low  
profile inductors and multi-layer ceramic capacitors. This  
results in a compact, low cost power system for LCD panel  
design.  
The ISL78010 provide a highly integrated multiple output  
power solution for TFT-LCD automotive applications. The  
system consists of one high efficiency boost converter and  
three linear-regulator controllers (V , V  
, and V )  
ON OFF  
LOGIC  
with multiple protection functions. A block diagram is shown  
in Figure 20. Table 1 lists the recommended components.  
The ISL78010 is designed for continuous current mode, but  
it can also operate in discontinuous current mode at light  
load. In continuous current mode, current flows continuously  
in the inductor during the entire switching cycle in steady  
state operation. The voltage conversion ratio in continuous  
current mode is given by Equation 1:  
The ISL78010 integrates an N-Channel MOSFET boost  
converter to minimize external component count and cost.  
The A  
, V , V  
, and V  
output voltages are  
VDD ON OFF  
LOGIC  
independently set using external resistors. V , V  
ON OFF  
voltages require external charge pumps which are post  
regulated using the integrated LDO controllers.  
A
1
VDD  
---------------  
-------------  
=
(EQ. 1)  
V
1 D  
IN  
TABLE 1. RECOMMENDED TYPICAL APPLICATION  
DIAGRAM COMPONENTS  
where D is the duty cycle of the switching MOSFET.  
DESIGNATION  
C , C , C  
DESCRIPTION  
Figure 21 shows the block diagram of the boost regulator. It  
uses a summing amplifier architecture consisting of GM  
stages for voltage feedback, current feedback and slope  
compensation. A comparator looks at the peak inductor  
current cycle by cycle and terminates the PWM cycle if the  
current limit is reached.  
10µF, 16V X7R ceramic capacitor (1206)  
TDK C3216X7RIC106M  
1
2
3
C
, C  
20 31  
4.7µF, 25V X5R ceramic capacitor (1206)  
TDK C3216X5R1A475K  
D
1A, 20V low leakage Schottky rectifier (CASE  
457-04) ON SEMI MBRM120ET3  
1
An external resistor divider is required to divide the output  
voltage down to the nominal reference voltage. Current  
drawn by the resistor network should be limited to maintain  
the overall converter efficiency. The maximum value of the  
resistor network is limited by the feedback input bias current  
and the potential for noise being coupled into the feedback  
pin. A resistor network in the order of 60kΩ is recommended.  
The boost converter output voltage is determined by  
Equation 2:  
D
, D , D  
200mA, 30V Schottky barrier diode (SOT-23)  
Fairchild BAT54S  
11 12 21  
L
6.8µH, 1.3A Inductor  
TDK SLF6025T-6R8M1R3-PF  
1
Q
-2.4, -20V P-Channel 1.8V specified  
PowerTrench MOSFET (SuperSOT-3)  
Fairchild FDN304P  
1
Q
Q
Q
200mA, 40V NPN amplifier (SOT-23)  
Fairchild MMBT3904  
2
3
4
R
+ R  
2
R
1
1
(EQ. 2)  
--------------------  
A
=
× V  
VDD  
REF  
200mA, 40V PNP amplifier (SOT-23)  
Fairchild MMBT3906  
The current through the MOSFET is limited to 2A peak. This  
restricts the maximum output current based on Equation 3:  
-2A, -30V single P-Channel logic level  
PowerTrench MOSFET (SuperSOT-3)  
Fairchild FDN360P  
ΔI  
V
IN  
V
O
L
--------  
---------  
I
=
I
LMT  
×
OMAX  
(EQ. 3)  
2
Q
1A, 30V PNP low saturation amplifier (SOT-23)  
Fairchild FMMT549  
5
Where ΔIL is peak to peak inductor ripple current, and is set  
by Equation 4:  
V
D
f
S
IN  
(EQ. 4)  
--------- ----  
ΔI  
=
×
L
L
where f is the switching frequency.  
S
FN6501.0  
May 30, 2007  
8
ISL78010  
EN  
REFERENCE  
GENERATOR  
VREF  
SGND  
OSCILLATOR  
SLOPE COMP OSC  
COMPENSATION  
LX  
PWM  
LOGIC  
Σ
BUFFER  
CONTROLLER  
VOLTAGE  
AMPLIFIER  
FBB  
GM  
AMPLIFIER  
CINT  
CURRENT  
AMPLIFIER  
PGND  
DRVP  
UVLO  
COMPARATOR  
EN  
CURRENT REF  
VDD  
PG  
CURRENT  
LIMIT COMPARATOR  
SHUTDOWN  
AND  
START-UP  
CONTROL  
+
-
VREF  
BUFFER  
THERMAL  
SHUTDOWN  
FBP  
UVLO  
COMPARATOR  
DELB  
CDLY  
DRVN  
SS  
+
SS  
+
0.2V  
VREF  
DRVL  
FBL  
-
-
BUFFER  
BUFFER  
FBN  
0.4V  
UVLO  
COMPARATOR  
UVLO  
COMPARATOR  
FIGURE 20. BLOCK DIAGRAM  
FN6501.0  
May 30, 2007  
9
ISL78010  
SHUTDOWN  
AND STARTUP  
CONTROL  
CLOCK  
SLOPE  
COMPENSATION  
IFB  
CURRENT  
AMPLIFIER  
PWM  
IREF  
LX  
LOGIC  
BUFFER  
IFB  
FBB  
GM  
AMPLIFIER  
IREF  
VOLTAGE  
AMPLIFIER  
REFERENCE  
GENERATOR  
PGND  
CINT  
FIGURE 21. BLOCK DIAGRAM OF THE BOOST REGULATOR  
FN6501.0  
May 30, 2007  
10  
ISL78010  
NOTE: Capacitors have a voltage coefficient that makes their  
effective capacitance drop as the voltage across them increases.  
in Equation 7 assumes the effective value of the capacitor at a  
Table 2 gives typical values (margins are considered 10%,  
3%, 20%, 10%, and 15%) on V , V , L, f , and I  
:
IN OMAX  
O
S
C
OUT  
TABLE 2. TYPICAL V , V , L, f , AND I  
VALUES  
particular voltage and not the manufacturer’s stated value, measured  
IN  
O
S
OMAX  
at zero volts.  
f
I
S
OMAX  
(A)  
Compensation  
V
(V)  
V
(V)  
O
L (µH)  
6.8  
(MHz)  
IN  
The ISL78010 can operate in either P-mode or PI-mode.  
P-mode may be preferred in applications where excellent  
transient load performance is required but regulation is not  
3.3  
3.3  
3.3  
5
9
1
1
1
1
1
1
0.490686  
0.307353  
0.197353  
0.743464  
0.465686  
0.29902  
12  
15  
9
6.8  
6.8  
critical. Connecting the C  
pin directly to V will enable  
INT  
IN  
P-mode; For better load regulation, use PI-mode with a  
6.8  
4.7nF capacitor in series with a 10k resistor between C  
INT  
5
12  
15  
6.8  
and ground. This value may be reduced to improve transient  
performance, however, very low values will reduce loop  
stability. Figures 5 through 10 show a comparison of P-mode  
vs PI-mode performance.  
5
6.8  
Input Capacitor  
An input capacitor is used to supply the peak charging  
current to the converter. It is recommended that C be  
larger than 10µF. The reflected ripple voltage will be smaller  
with larger C . The voltage rating of input capacitor should  
Boost Feedback Resistors  
IN  
As the boost output voltage, A  
VDD  
, is reduced below 12V the  
effective voltage feedback in the IC increases the ratio of  
voltage to current feedback at the summing comparator  
IN  
be larger than the maximum input voltage.  
because R decreases relative to R . To maintain stable  
2
1
operation over the complete current range of the IC, the  
voltage feedback to the FBB pin should be reduced  
Boost Inductor  
The boost inductor is a critical part which influences the  
output voltage ripple, transient response, and efficiency.  
Values of 3.3µH to 10µH are to match the internal slope  
compensation. The inductor must be able to handle the  
following average and peak current:  
proportionally, as A  
is reduced, by means of a series  
resistor-capacitor network (R and C ) in parallel with R ,  
VDD  
7
7
1
with a pole frequency (f ) set to approximately 10kHz for C  
p
2
(effective) = 10µF and 4kHz for C (effective) = 30µF.  
2
1  
1
1
I
⎛⎛  
⎝⎝  
--------------------- ------  
(EQ. 5)  
(EQ. 8)  
O
R
C
=
=
-------------  
7
7
I
I
=
0.1 × R  
R
LAVG  
2
1
1 D  
ΔI  
L
1
(EQ. 6)  
--------  
+
= I  
------------------------------------------------  
2 × 3.142 × f × R  
LPK  
LAVG  
2
(EQ. 9)  
p
7
Rectifier Diode  
PI-Mode C  
(C ) and R )  
(R  
INT 23 INT 10  
A high-speed diode is necessary due to the high switching  
frequency. Schottky diodes are recommended because of  
their fast recovery time and low forward voltage. The rectifier  
diode must meet the output current and peak inductor  
current requirements.  
The IC is designed to operate with a minimum C capacitor  
23  
of 4.7nF and a minimum C (effective) = 10µF.  
2
Note that, for high voltage A  
, the voltage coefficient of  
VDD  
ceramic capacitors (C ) reduces their effective capacitance  
2
greatly; a 16V, 10µF ceramic can drop to around 3µF at 15V.  
Output Capacitor  
To improve the transient load response of A  
VDD  
in PI-mode,  
The output capacitor supplies the load directly and reduces  
the ripple voltage at the output. Output ripple voltage  
consists of two components: the voltage drop due to the  
inductor ripple current flowing through the ESR of output  
capacitor, and the charging and discharging of the output  
capacitor.  
a resistor may be added in series with the C capacitor. The  
23  
larger the resistor the lower the overshoot but at the expense  
of stability of the converter loop - especially at high currents.  
With L = 10µH, A  
VDD  
= 15V, C = 4.7nF, C (effective)  
23  
2
should have a capacitance of greater than 10µF. R  
(R )  
INT  
7
can have values up to 5kΩ for C (effective) up to 20µF and  
2
V
V  
I
O
1
f
S
O
IN  
(EQ. 7)  
up to 10k for C (effective) up to 30µF.  
----------------------- --------------- ----  
V
= I  
× ESR +  
LPK  
×
×
2
RIPPLE  
V
C
O
OUT  
Larger values of R  
INT  
(R ) may be possible if maximum  
7
A
load currents less than the current limit are used. To  
VDD  
ensure A  
For low ESR ceramic capacitors, the output ripple is  
stability, the IC should be operated at the  
VDD  
maximum desired current and then the transient load  
response of A should be used to determine the  
dominated by the charging and discharging of the output  
capacitor. The voltage rating of the output capacitor should  
be greater than the maximum output voltage.  
VDD  
maximum value of R  
.
INT  
FN6501.0  
May 30, 2007  
11  
ISL78010  
Operation of the DELB Output Function  
V
V
BOOST  
IN  
An open drain DELB output is provided to allow the boost  
output voltage, developed at C (See “Typical Application  
2
Diagram” on page 17), to be delayed via an external switch  
(Q ) to a time after the V supply and negative V  
charge pump supply have achieved regulation during the  
start-up sequence shown in Figures 14 and 16. This then  
LX  
4
BOOST  
OFF  
FB  
ISL78010  
allows the A  
and V  
supplies to start-up from 0V  
(D ) if Q  
VDD  
ON  
instead of the normal offset voltage of V -V  
IN DIODE  
1
4
were not present.  
When DELB is activated by the start-up sequencer, it sinks  
50µA allowing a controlled turn-on of Q and charge-up of  
FIGURE 22. CASCADED MOSFET TOPOLOGY FOR HIGH  
OUTPUT VOLTAGE APPLICATIONS  
4
C . C can be used to control the turn-on time of Q to  
9
16  
4
reduce inrush current into C . The potential divider formed  
9
Linear-Regulator Controllers (V , V  
, and  
ON LOGIC  
by R and R can be used to limit the V  
voltage of Q if  
9
8
GS  
4
V
)
OFF  
The ISL78010 includes three independent linear-regulator  
controllers, in which two are positive output voltage (V  
required by the voltage rating of this device. When the  
voltage at DELB falls to less than 0.6V, the sink current is  
increased to ~1.2mA to firmly pull DELB to 0V.  
ON  
, and  
and V  
V
), and one is negative. The V , V  
LOGIC  
ON OFF  
linear-regulator controller functional diagrams,  
The voltage at DELB is monitored by the fault protection  
LOGIC  
applications circuits are shown in Figures 23, 24, and 25  
respectively.  
circuit so that if the initial 50µA sink current fails to pull DELB  
below ~0.6V after the start-up sequencing has completed,  
then a fault condition will be detected and a fault time-out  
Calculation of the Linear Regulator Base-Emitter  
ramp will be initiated on the C  
capacitor (C ).  
7
DEL  
Resistors (R , R  
and R  
)
BL BP  
BN  
Operation of the PG Output Function  
For the pass transistor of the linear regulator, low frequency  
gain (h ) and unity gain frequency (f ) are usually specified  
The PG output consists of an internal pull-up PMOS device to  
FE  
T
in the datasheet. The pass transistor adds a pole to the loop  
transfer function at f = f /h . Therefore, in order to  
V , to turn-off the external Q protection switch and a current  
limited pull-down NMOS device which sinks ~15µA allowing a  
IN  
1
p
T FE  
maintain phase margin at low frequency, the best choice for  
a pass device is often a high frequency low gain switching  
transistor. Further improvement can be obtained by adding a  
controlled turn-on of Q gate capacitance. C is used to  
1
O
control how fast Q turns-on - limiting inrush current into C .  
1
1
When the voltage at the PG pin falls to less than 0.6V, the PG  
sink current is increased to ~1.2mA to firmly pull the pin to 0V.  
base-emitter resistor R (R , R , R  
in the Functional  
BE BP BL BN  
Block Diagrams on page 13), which increase the pole  
The voltage at PG is monitored by the fault protection circuit  
so that if the initial 15µA sink current fails to pull PG below  
~0.6V after the start-up sequencing has completed, then a  
fault condition will be detected and a fault time-out ramp will  
frequency to: f = f *(1+ h *re/R )/h , where  
p
T
FE BE FE  
re = KT/qIc. So choose the lowest value R in the design  
BE  
as long as there is still enough base current (I ) to support  
B
the maximum output current (I ).  
C
be initiated on the C  
capacitor (C ).  
7
DEL  
We will take as an example the V  
linear regulator. If a  
LOGIC  
Cascaded MOSFET Application  
Fairchild FMMT549 PNP transistor is used as the external  
pass transistor (Q in the application diagram) then for a  
A 20V N-Channel MOSFET is integrated in the boost  
regulator. For the applications where the output voltage is  
greater than 20V, an external cascaded MOSFET is needed  
as shown in Figure 22. The voltage rating of the external  
5
maximum V  
operating requirement of 500mA, the data  
LOGIC  
sheet indicates h (min) = 100.  
FE  
The base-emitter saturation voltage is: Vbe_max = 1.25V  
(note this is normally a Vbe ~ 0.7V, however, for the Q  
MOSFET should be greater than V  
.
BOOST  
5
transistor an internal Darlington arrangement is used to  
increase it's current gain, giving a 'base-emitter' voltage of  
2 x V ).  
BE  
(Note that using a high current Darlington PNP transistor for  
Q requires that V > V  
+ 2V. Should a lower input  
voltage be required, then an ordinary high gain PNP  
5
IN LOGIC  
transistor should be selected for Q so as to allow a lower  
5
collector-emitter saturation voltage).  
FN6501.0  
May 30, 2007  
12  
ISL78010  
For the ISL78010, the minimum drive current is:  
V
OR V  
PROT  
IN  
(3V TO 6V)  
I
(min) = 8mA  
DRVL  
(EQ. 10)  
LDO_LOG  
0.9V  
The minimum base-emitter resistor, R , can now be  
BL  
calculated as:  
R
BL  
500Ω  
PG_LDOL  
+
-
Q5  
(1.3V TO 3.6V)  
R
(min) = V (max) ⁄ (I  
(min) I h (min)) =  
DRVL C FE  
V
BL  
BE  
LOGIC  
DRVL  
(EQ. 11)  
1.25V ⁄ (8mA 500mA 100) = 417Ω  
C
LOG  
10µF  
R
R
This is the minimum value that can be used - so, we now  
choose a convenient value greater than this minimum value;  
say 500Ω. Larger values may be used to reduce quiescent  
current, however, regulation may be adversely affected, by  
L1  
L2  
FBL  
-
+
GML  
20kΩ  
supply noise if R is made too high in value.  
BL  
V
1: N1  
BOOST  
LX  
0.1µF  
LDO_ON  
0.9V  
FIGURE 25. V  
FUNCTIONAL BLOCK DIAGRAM  
LOGIC  
PG_LDOP  
CP (TO 36V)  
0.1µF  
+
-
36V  
ESD  
CLAMP  
The V  
ON  
power supply is used to power the positive supply  
R
of the row driver in the LCD panel. The DC/DC consists of an  
external diode-capacitor charge pump powered from the  
inductor (LX) of the boost converter, followed by a low  
dropout linear regulator (LDO_ON). The LDO_ON regulator  
uses an external PNP transistor as the pass element. The  
on-board LDO controller is a wide band (>10MHz)  
transconductance amplifier capable of 4mA drive current,  
which is sufficient for up to 40mA or more output current  
under the low dropout condition (forced beta of 10). Typical  
BP  
7kΩ  
Q3  
DRVP  
FBP  
V
(TO 35V)  
ON  
R
R
P1  
P2  
C
ON  
+
-
GMP  
20kΩ  
1: Np  
V
voltage supported by the ISL78010 ranges from +15V  
ON  
to +36V. A fault comparator is also included for monitoring  
the output voltage. The undervoltage threshold is set at 25%  
below the 1.2V reference.  
FIGURE 23. V  
FUNCTIONAL BLOCK DIAGRAM  
ON  
The V  
OFF  
power supply is used to power the negative  
supply of the row driver in the LCD panel. The DC/DC  
consists of an external diode-capacitor charge pump  
powered from the inductor (LX) of the boost converter,  
followed by a low dropout linear regulator (LDO_OFF). The  
LDO_OFF regulator uses an external NPN transistor as the  
pass element. The on-board LDO controller is a wide band  
(>10MHz) transconductance amplifier capable of 4mA drive  
current, which is sufficient for up to 40mA or more output  
current under the low dropout condition (forced beta of 10).  
LX  
0.1µF  
CP (TO -26V)  
LDO_OFF  
V
REF  
0.1µF  
PG_LDON  
0.4V  
-
+
R
N2  
20kΩ  
Typical V  
voltage supported by the ISL78010 ranges  
FBN  
OFF  
from -5V to -20V. A fault comparator is also included for  
monitoring the output voltage. The undervoltage threshold is  
set at 200mV above the 0.2V reference level.  
1: Nn  
R
N1  
V
(TO -20V)  
OFF  
-
+
The V  
power supply is used to power the logic circuitry  
LOGIC  
DRVN  
C
Q2  
OFF  
GMN  
within the LCD panel. The DC/DC may be powered directly  
from the low voltage input, 3.3V or 5.0V, or it may be  
powered through the fault protection switch. The  
R
BN  
3kΩ  
36V  
ESD  
CLAMP  
LDO_LOGIC regulator uses an external PNP transistor as  
the pass element. The on-board LDO controller is a wide  
band (>10MHz) transconductance amplifier capable of  
16mA drive current, which is sufficient for up to 160mA or  
FIGURE 24. V  
FUNCTIONAL BLOCK DIAGRAM  
OFF  
FN6501.0  
May 30, 2007  
13  
ISL78010  
more output current under the low dropout condition (forced  
beta of 10). Typical V voltage supported by the  
CHARGE PUMP  
OUTPUT  
VDD  
V
LOGIC  
ISL78010 ranges from +1.3V to V  
IN  
OR A  
- 0.2V. A fault  
DD  
comparator is also included for monitoring the output  
7kΩ  
voltage. The undervoltage threshold is set at 25% below the  
1.2V reference.  
Q3  
DRVP  
NPN  
CASCODE  
TRANSISTOR  
V
ON  
Set-Up Output Voltage  
Refer to the “Typical Application Diagram” on page 17, the  
ISL78010  
output voltages of V , V  
, and V  
are determined  
ON OFF  
LOGIC  
by Equations 12, 13 and 14:  
FBP  
R
12  
(EQ. 12)  
---------  
V
= V  
× 1 +  
ON  
REF  
R
11  
R
22  
(EQ. 13)  
(EQ. 14)  
---------  
V
= V  
+
× (V  
V  
REF  
)
OFF  
REFN  
REFN  
R
21  
FIGURE 26. CASCODE NPN TRANSISTOR CONFIGURATION  
FOR HIGH CHARGE PUMP OUTPUT VOLTAGE  
(>36V)  
R
42  
---------  
V
= V  
× 1 +  
LOGIC  
REF  
R
41  
where V  
= 1.2V, V = 0.2V.  
REFN  
LX  
REF  
0.1µF  
Resistor networks in the order of 250kΩ, 120kΩ and 10kΩ  
are recommended for V , V and V , respectively.  
A
ON OFF LOGIC  
VDD  
0.1µF  
Charge Pump  
To generate an output voltage higher than V  
7kΩ  
, single or  
BOOST  
multiple stages of charge pumps are needed. The number of  
stages is determined by the input and output voltage. For  
positive charge pump stages:  
0.1µF  
0.1µF  
DRVP  
Q3  
V
ON  
0.47µF  
(>36V)  
0.1µF  
ISL78010  
V
+ V  
V  
CE INPUT  
OUT  
(EQ. 15)  
-------------------------------------------------------------  
N
POSITIVE  
V
2 × V  
F
INPUT  
0.22µF  
FBP  
where V  
is the dropout voltage of the pass component of  
the linear regulator. It ranges from 0.3V to 1V depending on  
CE  
the transistor. V is the forward-voltage of the charge pump  
F
rectifier diode.  
FIGURE 27. THE LINEAR REGULATOR CONTROLS ONE  
STAGE OF CHARGE PUMP  
The number of negative charge pump stages is given by:  
V
+ V  
CE  
2 × V  
F
OUTPUT  
(EQ. 16)  
------------------------------------------------  
N
Discontinuous/Continuous Boost Operation and  
its Effect on the Charge Pumps  
NEGATIVE  
V
INPUT  
The ISL78010 V  
and V  
architecture uses LX  
OFF  
ON  
switching edges to drive diode charge pumps from which  
LDO regulators generate the V and V supplies. It can  
To achieve high efficiency and low material cost, the lowest  
number of charge pump stages which can meet the above  
requirements, is always preferred.  
ON  
OFF  
be appreciated that should a regular supply of LX switching  
High Charge Pump Output Voltage (>36V)  
Applications  
edges be interrupted, for example, during discontinuous  
operation at light A  
boost load currents, then this may  
affect the performance of V and V regulation -  
VDD  
In the applications where the charge pump output voltage is  
over 36V, an external NPN transistor needs to be inserted  
ON  
OFF  
depending on their exact loading conditions at the time.  
between DRVP pin and base of pass transistor Q as shown  
3
To optimize V /V  
regulation, the boundary of  
ON OFF  
discontinuous/continuous operation of the boost converter  
can be adjusted, by suitable choice of inductor given V  
in Figure 26; or the linear regulator can control only one  
stage charge pump and regulate the final charge pump  
output as shown in Figure 27.  
,
IN  
V
, switching frequency and the A  
current loading, to  
OUT VDD  
be in continuous operation.  
FN6501.0  
May 30, 2007  
14  
ISL78010  
Equation 17 gives the boundary between discontinuous and  
continuous boost operation. For continuous operation (LX  
switching every clock cycle) we require that:  
output until the boost is enabled internally. The delayed  
output appears at A  
.
VDD  
V
soft-starts at the beginning of the third ramp. The  
BOOST  
soft-start ramp depends on the value of the C  
I
(load) > D × (1 D) × V  
IN  
capacitor.  
AVDD  
DLY  
of 220nF, the soft-start time is ~2ms.  
(EQ. 17)  
--------------------------------------------------------------------------------------  
2 × L × f  
For C  
OSC  
DLY  
V
and V  
turn on when input voltage (V )  
DD  
REF  
LOGIC  
where the duty cycle, D = (A  
- V )/A  
IN VDD  
VDD  
exceeds 2.5V. When a fault is detected, the outputs and the  
input protection will turn off but V will stay on.  
For example, with V = 5V, f  
IN  
we find continuous operation of the boost converter can be  
guaranteed for:  
= 1.0MHz and A = 12V  
VDD  
OSC  
REF  
turns on at the start of the fourth peak. At the fifth  
V
OFF  
peak, the open drain o/p DELB goes low to turn on the  
external PMOS Q to generate a delayed V output.  
(EQ. 18)  
(EQ. 19)  
(EQ. 20)  
L = 10μH and I  
> 61mA  
> 89mA  
> 184mA  
AVDD  
4
BOOST  
V
is enabled at the beginning of the sixth ramp. A  
, DELB and V  
OFF ON  
,
ON  
PG, V  
VDD  
are checked at end of this ramp.  
L = 6.8μH and I  
L = 3.3μH and I  
AVDD  
AVDD  
Fault Protection  
Once the start-up sequence is complete, the voltage on the  
capacitor remains at 1.15V until either a fault is  
Charge Pump Output Capacitors  
C
DLY  
detected or the EN pin is disabled. If a fault is detected, the  
voltage on C rises to 2.4V at which point the chip is  
Ceramic capacitors with low ESR are recommended. With  
ceramic capacitors, the output ripple voltage is dominated by  
the capacitance value. The capacitance value can be  
chosen by Equation 21:  
DLY  
disabled until the power is recycled or enable is toggled.  
Component Selection for Start-Up Sequencing and  
Fault Protection  
I
OUT  
(EQ. 21)  
------------------------------------------------------  
C
OUT  
2 × V  
× f  
OSC  
RIPPLE  
The C  
capacitor is typically set at 220nF and is required  
to stabilize the V output. The range of C is from  
REF  
REF  
22nF to 1µF and should not be more than five times the  
capacitor on C to ensure correct start-up operation.  
REF  
where f  
is the switching frequency.  
OSC  
DEL  
capacitor is typically 220nF and has a usable  
Start-Up Sequence  
Figure 28 shows a detailed start-up sequence waveform. For  
a successful power up, there should be six peaks at V  
The C  
DEL  
.
range from 47nF minimum to several microfarads - only  
CDLY  
When a fault is detected, the device will latch off until either  
EN is toggled or the input supply is recycled.  
limited by the leakage in the capacitor reaching µA levels.  
C
should be at least 1/5 of the value of C  
(See  
the fault time-out will  
DEL  
above). Note that with 220nF on C  
REF  
When the input voltage is higher than 2.5V, an internal  
DEL  
current source starts to charge C  
using a fast ramp followed by a slow ramp. During the initial  
slow ramp, the device checks whether there is a fault  
to an upper threshold  
be typically 50ms and the use of a larger/smaller value will  
vary this time proportionally (e.g. 1µF will give a fault time-  
out period of typically 230ms).  
CDLY  
condition. If no fault is found, C  
is discharged after the  
CDLY  
Fault Sequencing  
first peak and V  
REF  
turns on.  
The ISL78010 has advanced fault detection systems which  
protects the IC from both adjacent pin shorts during  
operation and shorts on the output supplies.  
During the second ramp, the device checks the status of  
and over-temperature. At the peak of the second  
V
REF  
ramp, PG output goes low and enables the input protection  
PMOS Q . Q is a controlled FET used to prevent in-rush  
A high quality layout/design of the PCB, in respect of  
grounding quality and decoupling is necessary to avoid  
falsely triggering the fault detection scheme - especially  
during start-up. The user is directed to the “Layout  
Recommendation” on page 17 and “Component Selection  
for Start-Up Sequencing and Fault Protection” on page 15 to  
avoid problems during initial evaluation and prototype PCB  
generation.  
1
1
current into V  
before V  
is enabled internally.  
BOOST  
BOOST  
Its rate of turn on is controlled by C . When a fault is  
o
detected, M1 will turn off and disconnect the inductor from  
V
.
IN  
With the input protection FET on, NODE1 (See “Typical  
Application Diagram” on page 17) will rise to ~V . Initially  
IN  
the boost is not enabled so V  
BOOST  
rises to V -V  
IN DIODE  
through the output diode. Hence, there is a step at V  
BOOST  
during this part of the start-up sequence. If this step is not  
desirable, an external P-MOSFET can be used to delay the  
FN6501.0  
May 30, 2007  
15  
ISL78010  
V
CDLY  
V
IN  
EN  
V
REF  
V
BOOST  
t
ON  
t
OS  
V
LOGIC  
V
OFF  
t
DEL1  
DELAYED  
V
BOOST  
t
DEL2  
V
t
ON  
DEL3  
START-UP SEQUENCE  
TIMED BY C  
DLY  
FIGURE 28. START-UP SEQUENCE  
FN6501.0  
May 30, 2007  
16  
ISL78010  
4. All feedback networks should sense the output voltage  
Over-Temperature Protection  
directly from the point of load, and be as far away from LX  
node as possible.  
An internal temperature sensor continuously monitors the  
die temperature. In the event that the die temperature  
exceeds the thermal trip point of +140°C, the device will shut  
down.  
5. The power ground (PGND) and signal ground (SGND)  
pins should be connected at only one point near the main  
decoupling capacitors.  
Layout Recommendation  
6. A signal ground plane, separate from the power ground  
plane, should be used for ground return connections for  
feedback resistor networks (R , R , R ) and the V  
REF  
Device performance including efficiency, output noise,  
transient response and control loop stability is dramatically  
affected by the PCB layout. PCB layout is critical, especially  
at high switching frequency.  
1
11 41  
capacitor, C , the C  
capacitor C and the  
22 DELAY  
7
integrator capacitor C  
.
23  
7. Minimize feedback input track lengths to avoid switching  
noise pick-up.  
There are some general guidelines for layout:  
8. Connect all "NC" pins to the ground plane to improve the  
thermal performance and switching noise immunity  
between pins.  
1. Place the external power components (the input  
capacitors, output capacitors, boost inductor and output  
diodes, etc.) in close proximity to the device. Traces to  
these components should be kept as short and wide as  
possible to minimize parasitic inductance and resistance.  
A demo board is available to illustrate the proper layout  
implementation.  
2. Place V  
and V  
bypass capacitors close to the pins.  
DD  
REF  
3. Minimize the length of traces carrying fast signals and  
high current.  
Typical Application Diagram  
LX  
A
VDD  
(12V)  
L
D
1
1
Q
NODE 1  
Q
4
1
V
IN  
C
9
C
C
6.8µH  
0
1
C -C  
2
10µF  
X2  
R
C
3
9
16  
22nF  
46.5kΩ  
R
2
0.1µF  
1nF  
10µF  
x2  
1MΩ  
PG  
LX  
FBB  
R
OPEN  
OPEN  
7
R
1
5kΩ  
R
8
C
7
C
7
10kΩ  
CDELAY  
VDD  
C
10  
0.22µF  
4.7µF  
DELB  
CINT  
R
10Ω  
6
6
7
LX  
R
10  
4.7nF  
1nF  
C
23  
C
R
4.7µF  
10kΩ  
10kΩ  
C
P
C
C
11  
13  
0.1µF  
0.1µF  
EN  
R
13  
V
0.1µF  
REF  
C
41  
C
C
14  
0.1µF  
12  
0.1µF  
7kΩ  
NODE 1  
VREF  
C
D
D
11  
22  
0.1µF  
12  
R
DRVP  
FBP  
Q
43  
3
V
(15V)  
ON  
R
230kΩ  
12  
500Ω  
*
R
C
15  
11  
20kΩ  
C
24  
Q
DRVL  
FBL  
5
0.47µF  
R
LX  
42  
V
LOGIC  
(2.5V)  
*
0.1µF  
R
41  
5kΩ  
C
5.4kΩ  
31  
4.7µF  
R
23  
C
*
25  
0.1µF  
3kΩ  
*
D
21  
DRVN  
FBN  
Q
V
2
OFF  
(-5V)  
R
104k  
22  
R
C
21  
20k  
20  
4.7µF  
SGND  
PGND  
*
V
REF  
NOTE: SGND should be connected to PGND at one point only.  
FN6501.0  
May 30, 2007  
17  
ISL78010  
Thin Plastic Quad Flatpack Packages (TQFP)  
Q32.5x5 (JEDEC MS-026AAA ISSUE B)  
32 LEAD THIN PLASTIC QUAD FLATPACK PACKAGE  
MILLIMETERS  
D
D1  
SYMBOL  
MIN  
-
MAX  
1.20  
0.15  
1.05  
0.27  
0.23  
7.10  
5.10  
7.10  
5.10  
0.75  
NOTES  
-D-  
A
A1  
A2  
b
-
0.05  
0.95  
0.17  
0.17  
6.90  
4.90  
6.90  
4.90  
0.45  
-
-B-  
-
-A-  
6
b1  
D
-
E
E1  
3
D1  
E
4, 5  
3
e
E1  
L
4, 5  
-
PIN 1  
N
32  
7
e
0.50 BSC  
-
SEATING  
PLANE  
-H-  
A
Rev. 0 2/07  
NOTES:  
0.08  
0.003  
1. Controlling dimension: MILLIMETER. Converted inch  
dimensions are not necessarily exact.  
-C-  
2. All dimensions and tolerances per ANSI Y14.5M-1982.  
3. Dimensions D and E to be determined at seating plane  
0.08  
0.003  
.
-C-  
D
S
A-B  
C
S
M
4. Dimensions D1 and E1 to be determined at datum plane -H- .  
b
o
o
5. Dimensions D1 and E1 do not include mold protrusion. Allowable  
protrusion is 0.25mm (0.010 inch) per side.  
11 -13  
0.020  
b1  
MIN  
0.008  
o
6. Dimension b does not include dambar protrusion. Allowable dam-  
bar protrusion shall not cause the lead width to exceed the max-  
imum b dimension by more than 0.08mm (0.003 inch).  
0
MIN  
0.09/0.16  
0.004/0.006  
A2  
A1  
GAGE  
PLANE  
7. “N” is the number of terminal positions.  
BASE METAL  
WITH PLATING  
L
0.09/0.20  
o
o
11 -13  
0.25  
0.010  
0.004/0.008  
o
o
0 -7  
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.  
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality  
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without  
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and  
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result  
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.  
For information regarding Intersil Corporation and its products, see www.intersil.com  
FN6501.0  
May 30, 2007  
18  

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