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Электронный компонент: L5993D

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L5993
CONSTANT POWER CONTROLLER
CURRENT-MODE CONTROL PWM
SWITCHING FREQUENCY UP TO 1MHz
LOW START-UP CURRENT (< 120
A)
CONSTANT OUTPUT POWER VS. SWITCH-
ING FREQUENCY
HIGH-CURRENT OUTPUT DRIVE SUITABLE
FOR POWER MOSFET (1A)
FULLY LATCHED PWM LOGIC WITH DOU-
BLE PULSE SUPPRESSION
PROGRAMMABLE DUTY CYCLE
100%AND 50% MAXIMUM DUTY CYCLE LIMIT
PROGRAMMABLE SOFT START
PRIMARY OVERCURRENT FAULT DETEC-
TION WITH RE-START DELAY
PWM UVLO WITH HYSTERESIS
IN/OUT SYNCHRONIZATION
LATCHED DISABLE
INTERNAL 100ns LEADING EDGE BLANK-
ING OF CURRENT SENSE
PACKAGE: DIP16 AND SO16N
DESCRIPTION
This primary controller I.C., developed in BCD60II
technology, has been designed to implement off
line or DC-DC power supply applications using a
fixed frequency current mode control.
Based on a standard current mode PWM control-
ler this device includes some features such as
programmable soft start, IN/OUT synchronization,
disable (to be used for over voltage protection and
for power management), precise maximum Duty
Cycle Control, 100ns leading edge blanking on
current sense, pulse by pulse current limit, over-
current protection with soft start intervention and
"constant power" function for cotrolling throughput
power in multisync monitor SMPS.
July 1999
+
-
+
-
TIMING
2
3
+
-
14
T
Vref
CLK
2.5V
+
-
1.2V
13
BLANKING
PWM
FAULT
SOFT-START
R
S
Q
25V
15V/10V
VREF OK
DIS
+
-
E/A
1V
R
2R
DIS
2.5V
7
6
5
11
10
9
4
8
15
1
13V
PWM UVLO
12
SGND
COMP
SS
ISEN
DIS
DC
RCT
SYNC
DC-LIM
V
CC
VREF
D97IN765
VFB
PGND
OUT
V
C
OVER CURRENT
+
-
16
C-POWER
BLOCK DIAGRAM
ORDERING NUMBERS: L5993 (DIP16)
L5993D (SO16)
MULTIPOWER BCD TECHNOLOGY
DIP16
SO16N
1/22
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage (I
CC
< 50mA) (*)
selflimit
V
I
OUT
Output Peak Pulse Current
1.5
A
Analog Inputs & Outputs (6,7)
-0.3 to 8
V
Analog Inputs & Outputs (1,2,3,4,5,15,14, 13, 16)
-0.3 to 6
V
P
tot
Power Dissipation @ T
amb
= 70
C (DIP16)
@ T
amb
= 50
C (SO16)
1
0.83
W
W
T
j
Junction Temperature, Operating Range
-40 to 150
C
T
stg
Storage Temperature, Operating Range
-55 to 150
C
(*) maximum package power dissipation limits must be observed
THERMAL DATA
Symbol
Parameter
Value
Unit
R
th j-amb
Thermal Resistance Junction -Ambient (DIP16)
Thermal Resistance Junction -Ambient (SO16)
80
120
C/W
C/W
PIN FUNCTIONS
N.
Name
Fun ction
1
SYNC
Synchronization. A synchronization pulse terminates the PWM cycle and discharges Ct
2
RCT
Oscillator pin for external C
t
, R
t
components
3
DC
Duty Cycle control
4
VREF
5.0V +/-1.5% reference voltage at 25
C
5
VFB
Error Amplifier Inverting input
6
COMP
Error Amplifier Output
7
SS
Soft start pin for external capacitor Css
8
V
CC
Supply for internal "Signal" circuitry
9
V
C
Supply for Power section
10
OUT
High current totem pole output
11
PGND
Power ground
12
SGND
Signal ground
13
ISEN
Current sense
14
DIS
Disable. It must never be left floating. Tie to SGND if not used.
15
DC-LIM
Connecting this pin to Vref, DC is limited to 50%. If it is left floating or grounded no limitation is
imposed
16
C-POWER
Constant Power vs. Switching Frequency. Connect a capacitor to SGND. The pin must be
connected to VREF if not used.
SYNC
RCT
DC
VREF
VFB
SS
COMP
1
3
2
4
5
6
7
OUT
SGND
PGND
ISEN
DIS
DC-LIM
C-POWER
16
15
14
13
12
10
11
D97IN783
V
CC
8
V
C
9
PIN CONNECTION
L5993
2/22
ELECTRICAL CHARACTERISTICS (V
CC
= 15V; T
j
= 0 to 105
C; R
T
= 13.3k
; C
T
= 1nF
unless otherwise specified.)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
REFERENCE SECTION
V
Ref
Output Voltage
T
j
= 25
C; I
O
= 1mA
4.925
5.0
5.075
V
Line Regulation
V
CC
= 12 to 20V; T
j
= 25
C
2.0
10
mV
Load Regulation
I
O
= 1 to 10mA; T
j
= 25
C
2.0
10
mV
T
S
Temperature Stability
0.4
mV/
C
Total Variation
Line, Load, Temperature
4.80
5.0
5.130
V
I
OS
Short Circuit Current
Vref = 0V
30
150
mA
Power Down/UVLO
V
CC
= 8.5V; I
sink
= 0.5mA
0.2
0.5
V
OSCILLATOR SECTION
Initial Accuracy
pin 15 = Vref
T
j
= 25
C
V
CC
= 12 to 20V
95
93
100
100
105
107
kHz
kHz
Duty Cycle
pin 3 = 0,7V, pin 15 = Vref
pin 3 = 0.7V, pin 15 = OPEN
0
0
%
%
Duty Cycle
pin 3 = 3.2V, pin 15 = Vref
pin 3 = 3.2V, pin 15 = OPEN
47
93
%
%
Duty Cycle Accuracy
pin 3 = 2.79V, pin 15 = OPEN
75
80
85
%
Oscillator Ramp Peak
2.8
3.0
3.2
V
Oscillator Ramp Valley
0.75
0.9
1.05
V
ERROR AMPLIFIER SECTION
Input Bias Current
V
FB
to GND
0.2
3.0
A
V
I
Input Voltage
V
COMP
= V
FB
2.42
2.5
2.58
V
G
OPL
Open Loop Gain
V
COMP
= 2 to 4V
60
90
dB
SVR
Supply Voltage Rejection
V
CC
= 12 to 20V
85
dB
V
OL
Output Low Voltage
I
sink
= 2mA, V
FB
= 2.7V
1.1
V
V
OH
Output High Voltage
I
sou rce
= 0.5mA, V
FB
= 2.3V
5
6
V
I
O
Output Source Current
V
COMP
> 4V, V
FB
= 2.3V
0.5
1.3
2.5
mA
Output Sink Current
V
COMP
> 1.1V, V
FB
= 2.7V
2
6
mA
Unit Gain Bandwidth
1.7
4
MHz
S
R
Slew Rate
8
V/
s
PWM CURRENT SENSE SECTION
I
b
Input Bias Current
I
sen
= 0
3
15
A
I
S
Maximum Input Signal
V
COMP
= 5V
0.92
1.0
1.08
V
Delay to Output
70
100
ns
Gain
2.85
3
3.15
V/V
SOFT START
I
SSC
SS Charge Current
14
20
26
A
I
SSD
SS Discharge Current
VSS = 0.6V, T
j
= 25
C
5
10
15
A
V
SSSAT
SS Saturation Voltage
DC = 0%
0.6
V
V
SSCLAMP
SS Clamp Voltage
7
V
LEADING EDGE BLANKING
Internal Masking Time
100
ns
OUTPUT SECTION
V
OL
Output Low Voltage
I
O
= 250mA
1.0
V
V
OH
Output High Voltage
I
O
= 20mA; V
CC
= 12V
10
10.5
V
I
O
= 200mA; V
CC
= 12V
9
10
V
V
OUT CLAMP
Output Clamp Voltage
I
O
= 5mA; V
CC
= 20V
13
V
L5993
3/22
ELECTRICAL CHARACTERISTICS (continued.)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
OUTPUT SECTION
Collector Leakage
V
CC
= 20V V
C
= 24V
2
20
A
Fall Time
C
O
= 1nF
C
O
= 2.5nF
20
35
60
ns
ns
Rise Time
C
O
= 1nF
C
O
= 2.5nF
50
70
100
ns
ns
UVLO Saturation
V
CC
= 0V to V
CCON
; I
sink
= 10mA
1.0
V
SUPPLY SECTION
V
CCON
Startup voltage
14
15
16
V
V
CCOFF
Minimum Operating Voltage
9
10
11
V
V
hys
ULVO Hysteresis
4.5
5
V
I
S
Start Up Current
Before Turn-on at:
V
CC
= V
CCON
- 0.5V
40
75
120
A
I
op
Operating Current
CT = 1nF,R
T
= 13.3k
, C
O
=1nF
9
13
mA
I
q
Quiescent Current
(After turn on), CT = 1nF,
R
T
= 13.3k
, C
O
= 0nF
7.0
10
mA
V
Z
Zener Voltage
I
8
= 20mA
21
25
30
V
SYNCHRONIZATION SECTION
Master Operation
V
1
Clock Amplitude
I
SOURCE
= 0.8mA
4
V
I
1
Clock Source Current
Vclock = 3.5V
3
7
mA
Slave Operation
V
1
Sync Pulse
Low Level
1
V
High Level
3.5
V
I
1
Sync Pulse Current
VSYNC = 3.5V
0.5
mA
OVER CURRENT PROTECTION
V
t
Fault Threshold Voltage
1.1
1.2
1.3
V
DISABLE SECTION
Shutdown threshold
2.4
2.5
2.6
V
I
SH
Shutdown Current
V
CC
= 15V
330
A
CONSTANT POWER
6
8
20
30
V14 = 0, Pin2 = open
Tj = 25
C
0
4
8
12
16
20
24
0
0.05
0.1
0.15
0.2
4
Vcc [V]
Iq [mA]
28
Figure 1. Quiescent current vs. input voltage.
0
4
8
12
16
20
24
0
50
100
150
200
250
300
350
V cc [V]
Iq [
A ]
V 14 = Vref
Tj = 25
C
Figure 2. Quiescent current vs. input voltage
(after disable).
L5993
4/22
8
1 0
1 2
1 4
1 6
1 8
2 0
2 2
2 4
7 .0
7 .5
8 .0
8 .5
9 .0
V c c
[V ]
Iq [m A ]
V 1 4 = 0 , V 5 = V re f
R t = 4 .5 K o h m ,T j = 2 5
C
5 0 0 K h z
3 0 0 K h z
1 M h z
1 0 0 K h z
Figure 3. Quiescent current vs. input voltage.
0
5
10
15
20
25
4.9
4.95
5
5.05
5.1
Iref [mA]
Vref [V]
Vcc=15V
Tj = 25
C
Figure 6. Reference voltage vs. load current.
-50
-25
0
25
50
75
100
125
150
4.9
4.95
5
5.05
5.1
Tj (
C)
Vref [V])
Vcc = 15V
Iref = 1mA
Figure 7. Vref vs. junction temperature.
-50
-25
0
25
50
75
100
125
150
4.9
4.95
5
5.05
5.1
Tj (
C)
Vref [V]
Vcc = 15V
Iref= 20mA
Figure 8. Vref vs. junction temperature.
8
10
12
14
16
18
20
22
0
6
12
18
24
30
36
Vcc [V]
Iq [mA ]
Co = 1nF, Tj = 2 5
C
DC = 10 0%
1M Hz
500K Hz
30 0K Hz
10 0KHz
Figure 5. Quiescent current vs. input voltage
and switching frequency.
8
1 0
12
14
1 6
18
2 0
22
0
6
1 2
1 8
2 4
3 0
3 6
V cc [ V ]
Iq [m A ]
C o = 1 n F, T j = 2 5
C
D C = 0 %
1 M H z
5 0 0 K H z
3 0 0 K H z
1 0 0 K H z
Figure 4. Quiescent current vs. input voltage
and switching frequency.
L5993
5/22