NJM2811
7.5A High Power DC/DC Converter Controller IC
■GENERAL
DESCRIPTION
The
NJM2811
is a high power step down DC/DC converter IC.
It incorporates 7.5A power transistor,
±2%
accuracy precision
voltage reference, fixed frequency PWM controller with
cycle-by-cycle current limit and low power consumption stand by
function.
The
NJM2811
realizes a high power step down application with
minimal external components.
NJM2811TLA2050
Pin 1 locates on the left side of the package drawing
(top front view).
■PACKAGE
OUTLINE
PIN FUNCTION
1:V
FB
2:SW
OUT
3:GND
4:V
+
5:STBY (V
COMP
)
■FEATURES
●
Adjustable output voltage
more than 5V
●
Operating Voltage
7.5V to 40V
●
PWM form Switching Power Supply Control
●
Internal High Power Transistor
7.5A (min.)
●
Fixed Frequency Oscillator
72kHz (typ.)
●
Current Sense Amplifier
●
Under Voltage Lockout
●
Thermal Shutdown Circuit
●
Bipolar Technology
●
Package Outline
TO-220(5PIN)
■BLOCK
DIAGRAM
7.5A Power Transistor
Current Sense
Amplifier
Current Detection
Transistor
4
2
Thermal
Shutdown
Reference
Voltage
ON/OFF
VREF
Oscillator
S
R
Latch Circuit
Q
Under Voltage
Lockout
Standby Circuit
PWM Comparator
VREF
1
Error Amplifier
5
3
-1-
NJM2811
■ABSOLUTE
MAXIMUM RATINGS (Ta=25°C)
PARAMETER
SYMBOL
Maximum Supply Voltage
V
+
Switch Output Voltage
Vo
(SWITCH)
Voltage Feedback and
V
FB
,V
COMP
Compensation Input Voltage Range
Power Dissipation
Operating Junction Temperature
Operating Temperature Range
Storage Temperature Range
P
D
Tj
Topr
Tstg
MAXIMUM RATINGS
40
-0.5
∼
+Vin
-0.3
∼
+7.0
TO-220 (5PIN)
16(T
C
≤
46°C)
-40
∼
+150
-40 ~ +85
-50 ~ +150
UNIT
V
V
V
W
°C
°C
°C
■THERMAL
CHARACTERISTICS
Thermal
Resistance
Junction-to-Ambient Temperature
Junction-to-Case
θja
θjc
70
6.5
°C/W
■POWER
DISSIPATION vs. AMBIENT TEMPERATURE
(T
opr
=-40~+85°C, Tj= ~+150°C, P
D
=16W(T
C
≤
46°C))
18
16
Power Dissipation P
D
(W)
14
12
10
8
6
4
2
0
25
50
75
Ambient Temperature Ta (°C)
100
Without Heat Sink
θ
HS
=10°C/W
θ
HS
=5°C/W
∞
Heat Sink
θ
HS
=20°C/W
-2-
NJM2811
■ELECTRICAL
CHARACTERISTICS (V
+
=12V, Ta=25°C)
Oscillator Block
PARAMETER
Frequency
Error Amplifier Block
PARAMETER
Voltage Feedback
Input Threshold
Line Regulation
Input Bias Current
Ripple Rejection
Output Voltage Swing
SYMBOL
V
FB
(th)
REG·Line
I
B
PSRR
V
OH
V
OL
V
+
=7.5
∼
40V
V
FB
=V
FB
(th)+0.15V
V
+
=10
∼
20V
Isource=75µA,V
FB
=4.7V
Isink=0.4mA,V
FB
=5.3V
TEST CONDITION
MIN.
4.9
–
–
–
4.2
–
TYP.
5.0
0.03
0.15
80
4.9
1.6
MAX.
5.1
0.08
1.0
–
–
1.9
UNIT
V
%/V
µA
dB
V
V
SYMBOL
fosc
TEST CONDITION
V
+
=7.5V
MIN.
65
TYP.
72
MAX.
79
UNIT
kHz
PWM comparator Block
PARAMETER
Duty Cycle
Maximum
Minimum
Switch Output Block
PARAMETER
Output Voltage Saturation
OFF-State Leakage
Current Limit Threshold
Switching Times
Output Voltage Rise Time
Output Voltage Fall Time
Under Voltage Lockout Block
PARAMETER
Startup Threshold
Hysteresis
Total Device
PARAMETER
Standby-State
Power Supply Current
Operating-State
Power Supply Current
SYMBOL
Icc
(stby)
Icc
TEST CONDITION
STBY≤0.1V
MIN.
–
TYP.
36
MAX.
100
53
UNIT
µA
mA
SYMBOL
V
TH(UVLO)
V
H(UVLO)
+
SYMBOL
DC
(MAX)
DC
(MIN)
TEST CONDITION
V
FB
=0V
V
FB
=5.3V
MIN.
–
0
TYP.
95
0
MAX.
–
0
UNIT
%
%
SYMBOL
+
TEST CONDITION
MIN.
–
–
7.5
–
–
TYP.
V -2.2
0
8.5
100
50
+
MAX.
V -2.5
100
10
–
–
+
UNIT
V
µA
A
ns
ns
V
SAT
V =15V,Isource=7.5A
Isw
(off)
V
+
=40V,SW
OUT
=0V
Ipk
(SWITCH)
V
+
=15V
tr
tf
V
+
=40V,R
OUT
=7.7Ω,V
FB
=0V
V
+
=40V,R
OUT
=7.7Ω,V
FB
=0V
TEST CONDITION
V Increasing
V
+
Decreasing
MIN.
6.4
0.3
TYP.
6.8
0.5
MAX.
7.2
0.7
UNIT
V
V
V
+
=40V,V
FB
=0V
–
40
duty⋅cycle=MAX
Keep the limit of maximum power dissipation not to operate thermal shutdown.
Low duty cycle pulse test is used to close its junction temperature to ambient temperature.
-3-
NJM2811
■MARKING
2811-050
JRC
Product Number
(NJM2811TLA2050)
Logo
Lot Number
1 2 3 4 5
■TYPICAL
CHARACTERISTICS
Switch Output Saturation Voltage
vs. Output Source Current
Switch Output Saturation Voltage
(V)
V
0
-0.5
-1
-1.5
-2
(V
+
=15V, Ta=25
o
C)
Output Saturation Voltage
V
(V)
Error AMP Block Output Saturation Voltage
vs. Output Sink Current
2
1.5
1
(V =12V, V =5.5V, Ta=25 C)
FB
+
o
-2.5
-3
0
2
4
6
8
10
Output Source Current
SOURCE
(A)
I
Standby-State Power Supply Current
vs. Supply Voltage
SAT(ERROR)
SAT
0.5
0
0
0.5
1
1.5
Output Sink Current
SINK
(mA)
I
2
Duty Cycle vs. Compensation Voltage
100
Duty Cycle DC (%)
80
60
40
20
0
(V
+
=12V, Ta=25
o
C)
Standby-State Power Supply Current
(
µ
A)
I
180
150
120
90
60
30
0
0
5
10
(Ta=25
o
C)
CC(stby)
15
20
25
30
35
40
0
Supply Voltage V
+
(V)
1
2
3
4
5
Compensation Voltage V
COMP
(V)
-4-
NJM2811
■TYPICAL
CHARACTERISTICS
Voltage Feedback Input Threshold vs. Temperature
Voltage Feedback Input Threshold
V (V)
5.1
(V
+
=12V)
Input Bias Current I (µA)
Error AMP Block Input Bias Current vs. Temperature
0.4
0.3
0.2
0.1
0
-50 -25 0 25 50 75 100 125 150
o
Ambient Temperature Ta ( C)
(V
+
=12V, V =V (th)+0.15V)
FB
FB
FB
5
4.95
4.9
-50 -25 0 25 50 75 100 125 150
o
Ambient Temperature Ta ( C)
B
5.05
(A)
Oscillator Frequency vs. Temperature
(kHz)
80
75
70
65
60
-50 -25 0 25 50 75 100 125 150
o
Ambient Temperature Ta ( C)
(V
+
=12V)
Current Limit Threshold vs. Temperature
(SWITCH)
10
9
8
7
6
(V
+
=15V)
OSC
Current Limit Threshold Ipk
Oscillator Frequency f
5
-50 -25 0 25 50 75 100 125 150
o
Ambient Temperature Ta ( C)
Operating-State Power Supply Current
vs. Tmperature
Under Voltage Lockout Threshold
(V)
V
7.5
7
6.5
6
5.5
(mA)
8
Under Voltage Lockout Threshold
vs. Temperature
60
50
40
30
20
10
(V =40V, V =0V, duty cycle=MAX)
FB
+
V Increasing
Startup Threshold
V Decreasing
+
5
-50 -25 0 25 50 75 100 125 150
o
Ambient Temperature Ta ( C)
Power Supply Current I
+
TH(UVLO)
CC
Startup Threshold
0
-50 -25
0 25 50 75 100 125 150
o
Ambient Tmperature Ta ( C)
-5-
FPGA/CPLD
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