LM2648 National Semiconductor, LM2648 Datasheet - Page 5

• Manufacturer Part Number: LM2648
• Description: Synchronous Step-Down 3-Channel Switching Regulator Controller
• Manufacturer: National Semiconductor

I
V
I
I
I
I
Shutdown
V
V
S
S
V
Protection
I
I
V
V
V
V
V
V
I
Gate Drive
I
I
I
SK_TD12-3
ss1/2_sc
ss3_sc
ss1/2_sc
sc_TD12-3
SC_FAULTDELAY
SK_FAULTDELAY
sk_prot-in2
CBOOT
SC_DRV
sk_HDRV
Electrical Characteristics
TD12-3
Standby
ON
W_ R1, 2
W_R3a, 3b
SW_dis
FAULT_DELAY
UVP
OVP
UVLO_INT
PROT-IN1
PROT-IN2
Unless otherwise specified, V
type apply over the full operating junction temperature range. Specifications appearing in plain type are measured using low
duty cycle pulse testing with T
Symbol
/
/
Delay Timer Sink
Current
Delay Timer Threshold
Voltage
Soft-Start Source
Current Ratio
Soft-Start to Delay Timer
Source Current Ratio
Standby Threshold
(ON/UVLO pin)
Hysteresis
ON Threshold
(ON/UVLO pin)
Hysteresis
SW1, 2 ON Resistance
SW3a, 3b ON
Resistance
SW3a Quick Discharge
Threshold at FB3 (falling
edge)
FAULT_DELAY source
current
FAULT_DELAY sink
current
FAULT_DELAY
threshold Voltage
FB1, 2, 3 Under Voltage
Protection Latch
Threshold
Hysteresis
FB1, 2, 3 Over-voltage
Shutdown Latch
Threshold
VLIN5 Under Voltage
Lockout Threshold
Hysteresis
Analog protection
threshold
Logic protection
threshold
PROT-IN2 sink current
CBOOTx Leakage
Current
HDRVx and LDRVx
Source Current
HDRVx Sink Current
Parameter
IN
A
= 12V, SGND = PGND = 0V, VLIN5 = VDD1 = VDD2 = VDD3x. Limits appearing in boldface
= 25˚C (Note 5), (Note 6). Min/Max limits are guaranteed by design, test, or statistical analysis.
V
Rising
Rising
Shutdown to Standby
Rising
Standby to On
V
V
LDRV3a = High
FAULT_DELAY = 2.0V
FAULT_DELAY = 0.4V
Rising
As a percentage of nominal output
voltage (falling edge)
As a percentage of nominal output
voltage (rising edge)
Rising
V
HDRV = LDRV = 2.5V
HDRVX = 2.5V
(Continued)
TD
SW1
SW3a
CBOOTX
= 0.4V
= V
= V
SW2
= 7V
SW3b = 0.4V
Conditions
= 0.4V
5
-13%
-32%
1.70
0.95
1.75
3.54
1.75
1.19
Min
192
440
200
106
0.8
75
0.209
1.239
1.94
1.98
0.27
1.96
80.6
1.48
Typ
274
149
205
570
249
112
1.0
1.2
.81
4.7
4.2
0.5
0.8
10
4
8
2
+13%
+32%
Max
2.20
1.44
2.20
2.20
356
700
310
119
5.9
1.4
86
2
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Units
A/A
A/A
mV
mV
mA
µA
µA
µA
nA
%
%
%
%
V
V
V
Ω
Ω
V
V
V
V
V
A
A