lx1554 Microsemi Corporation, lx1554 Datasheet - Page 4

• Manufacturer Part Number: lx1554
• Description: Ultra-low Start-up Current, Current-mode Pwm
• Manufacturer: Microsemi Corporation

LX1552/3/4/5
4
Notes: 2. These parameters, although guaranteed, are not 100% tested in
Under-Voltage Lockout Section
Start Threshold
Min. Operation Voltage After Turn-On
PWM Section
Maximum Duty Cycle
Minimum Duty Cycle
Power Consumption Section
Start-Up Current
Operating Supply Current
V
*** - Toggle flip flop used only in 1554 and 1555.
CC
GROUND**
** - POWER GROUND and GROUND are internally connected for 8 pin packages.
* - V
Zener Voltage
3. Parameter measured at trip point of latch with V
4. Gain defined as: A =
5. Adjust V
6. Output frequency equals oscillator frequency for the LX1552 and
COMP
R
CC
I
production.
LX1553. Output frequency is one half oscillator frequency for the
LX1554 and LX1555.
V
T
SENSE
/C
CC
V
and V
FB
*
T
Parameter
C
are internally connected for 8 pin packages.
CC
above the start threshold before setting at 15V.
16V (1552/1554)
8.4V (1553/1555)
OSCILLATOR
ERROR AMP
34V
V
V
ISENSE
COMP
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
E L E C T R I C A L C H A R A C T E R I S T I C S
U
; 0
Symbol
LTRA
V
I
I
V
ST
CC
ST
Z
P
V
16V (1552/1554)
8.4V (1553/1555)
-L
ISENSE
UVLO
R O D U C T I O N
OW
1552/1554
1553/1555
1552/1554
1553/1555
1552/1553
1552/1553, R
1554/1555
I
CC
= 25mA
2R
S
0.8V.
R
TART
FB
B L O C K D I A G R A M
= 0.
GOOD LOGIC
-U
S / R
T
P
= 698 , C
Test Conditions
V
1V
C
REF
URRENT
REF
5V
D
T
= 22nF
7. Temperature stability, sometimes referred to as average temperature
, C
CURRENT SENSE
COMPARATOR
A T A
coefficient, is described by the equation:
V
voltage measured over the appropriate temperature range. Note that the
extremes in voltage do not necessarily occur at the extremes in
temperature.
URRENT
***
REF
(max.) & V
Temp Stability =
S
S
R
-M
T
H E E T
ODE
PWM
LATCH
REF
PWM
(min.) are the maximum & minimum reference
(Con't.)
Min. Typ. Max. Min. Typ. Max.
LX155xI/155xM
7.8
7.0
15
94
47
30
INTERNAL
9
V
BIAS
REF
T
A
150
8.4
7.6
16
10
96
50
48
11
35
(max.) - V
(max.) - T
250
9.0
8.2
17
11
17
0
A
REF
(min.)
7.8
7.0
15
94
47
30
(min.)
9
LX155xC
V
V
OUTPUT
POWER GROUND**
150
REF
C
8.4
7.6
16
10
96
50
48
11
35
*
250
9.0
8.2
17
11
17
0
Copyright © 1994
Rev. 1.0a 1/01
Units
mA
µA
%
%
%
%
V
V
V
V
V