RT6551A/B
Parameter
Symbol
VDD
TON
Shutdown Current
(V
S5
= V
S3
= 0V)
I
SHDN
S5/S3
VLDOIN
VID
FB Error Comparator
Threshold
VDDQ Voltage Range
Switch Frequency
Minimum Off-Time
VDDQ Shutdown Discharge
Resistance
Current Sensing
CS Pin Source Current
Zero Crossing Threshold
Fault Protection
Current Limit (Positive)
Output UV Threshold
UVP Latch Delay
OVP Threshold
OVP Latch Delay
VDD POR Threshold
Voltage Ramp Soft-Start Time
UV Blank Time
Thermal Shutdown
Driver On-Resistance
UGATE Gate Driver Source
UGATE Gate Driver Sink
LGATE Gate Driver Source
LGATE Gate Driver Sink
Dead Time
Internal Boost Charging Switch
On-Resistance
R
UGATEsr
R
UGATEsk
R
LGATEsr
R
LGATEsk
BOOT
PHASE
Forced to 5V
BOOT
PHASE Forced to 5V
DL, High State
DL, Low State
LGATE Rising (Phase = 1.5V)
UGATE Rising
VDD to BOOT, 10mA
--
--
--
--
--
--
--
2.5
1.5
2.5
0.8
40
40
--
5
3
5
1.6
--
--
80
ns
T
SD
V
OVP
V
UVP
GND
PHASE, R
CS
= 160k
V
FB
Falling. For both VID is high or
low.
FB Forced below UV Threshold
With Respect to Error Comparator
Threshold
FB Forced above OV Threshold
Rising Edge, Hysteresis = 120mV,
PWM Disabled below this Level
From S5 Going High to V
FB
= 0.675V
From S5 Signal Going High
70
0.4
--
110
--
3.9
--
--
--
80
0.45
30
115
5
4.2
1
5
165
90
0.5
--
120
--
4.5
--
--
--
mV
V
s
%
s
V
mS
mS
C
GND
PHASE
4.5
5
5
--
5.5
10
A
mV
V
S5
= 0V, V
S3
= 0V
f
SW
R
TON
= 620k, V
IN
= 12V,
V
DDQ
= 1.5V, I
OUT
= 20A
(Note 5)
V
REF
V
REF
= 0.675V/0.75V
Test Conditions
Min
--
--
1
--
--
1
0.675
320
250
--
Typ
0.1
0.1
0.1
0.1
0.5
0
--
400
400
15
Max
10
5
1
1
1
1
3.3
480
550
--
Unit
A
A
A
A
A
%
V
kHz
ns
Copyright
©
2015 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS6551A/B-00 May 2015
www.richtek.com
7
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
