ltc4269cdkd-2 Linear Technology Corporation, ltc4269cdkd-2 Datasheet - Page 12

• Manufacturer Part Number: ltc4269cdkd-2
• Description: Ieee 802.3at High Power Pd And Synchronous Forward Controller With Aux Support
• Manufacturer: Linear Technology Corporation

LTC4269-2
BLOCK DIAGRAMS
12
SD_V
SYNC
R
OSC
SEC
15
11
12
V
V
IN
IN
–
–
OFF
ON
1.32V
V
23
+
+
IN
EXPOSED PAD 33
1.23V
10
FB
START-UP
INPUT CURRENT (ISTART)
V
V
R
SHDN
PORTN
PORTN
I
10μA SD_V
0μA SD_V
CLASS
HYST
T2P 2
+
–
1
3
5
6
(VOLTAGE)
ERROR AMPLIFIER
SEC
SEC
> 1.32V
= 1.32V
–
+
(TYPICAL 200kHz)
OSC
(100 TO 500)kHz
CONTROL
COMP
CIRCUITS
1.23V
9
V
REF
14
REF
BOLD LINE INDICATES
HIGH CURRENT PATH
2.5V
SOURCE
2.5mA
SS_MAXDC
RAMP
+
–
13
GND
CLASSIFICATION
16
CURRENT LOAD
EN
–
+
35μA 80% DC
SLOPE COMP
8μA 0% DC
(LINEAR)
DUTY CYCLE
MAXIMUM
ADAPTIVE
0.45V
0mV TO 220mV
CLAMP
+
–
–
CURRENT
SENSE
S
R
25k
Q
+
Q
R
S
SOFT-START CONTROL
16k
DELAY
DELAY
ON
20
42692 BD1
BLANK
BLANK
32
29
28
27
26
17
V
PWRGD
PWRGD
V
V
PORTP
NEG
NEG
DRIVER
1A
13V
107mV
–
CURRENT
OVER
>90%
V
REF
50mA
+
12V
42692 BD2
19 OC
18
24 SOUT
22
21
42692f
OUT
PGND
I
SENSE