Quick-PWM Slave Controllers for
Multiphase, Step-Down Supplies
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V+ = 15V, V
CC
= V
DD
= 5V, V
OUT
= V
COMP
= 1.2V, V
CM+
= V
CM-
= V
CS+
= V
CS-
= 1.2V,
SHDN
= V
CC
(MAX1897),
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
CURRENT SENSING
On-Time Adjustment Range
COMP Output Current
I
COMP
0.42 < V
COMP
< 2.8V, V
OUT
≥
0.7V
Sink and source
(V
CM+
- V
CM-
) -
(V
CS+
- V
CS-
), I
COMP
=
0, -100mV
≤
(V
CM+
-
V
CM-
)
≤
+100mV
MAX1887
MAX1897
-40
30
-1.25
-1.25
1.2
-0.2
-1
V
ILIM
= 0.5V
V
ILIM
= 1V
V
ILIM
= 0.5V
V
ILIM
= 1V
47.5
97.5
-80
-160
0.2
-100
t
LIMIT
V
OL(LIMIT)
I
LIMIT
Falling edge, 3mV over trip threshold
I
SINK
= 1mA
LIMIT forced to 5.5V
Rising edge, hysteresis = 20mV, switching
disabled below this level
Rising, hysteresis = 15°C (typ)
MAX1887
MAX1897
MAX1887
MAX1897
MAX1887
MAX1897
< 0.01
1.5
0.1
1.00
50.0
100.0
-75
-150
+2.0
+1
52.5
102.5
-70
-140
0.3
+100
+1.25
mV
+1.25
mS
V
µA
mV
mV
V
nA
µs
V
µA
+40
%
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX1887/MAX1897
Current-Balance Offset
Current-Balance
Transconductance
Current-Sense, Common-Mode
Range
Current-Sense Input Current
Positive Current-Limit Threshold
Negative Current-Limit
Threshold
ILIM Standby Threshold Voltage
ILIM Input Current
LIMIT Propagation Delay
LIMIT Output Low Voltage
LIMIT Leakage Current
FAULT PROTECTION
V
CC
/V
DD
Undervoltage Lockout
Threshold (Note 3)
Thermal Shutdown Threshold
GATE DRIVERS
DH Gate-Driver On-Resistance
(Note 4)
R
ON(DH)
V
C_LIM
(V
CM+
- V
CM-
) - (V
CS+
- V
CS-
) = ±25mV
CM+, CM-, CS+, CS-
CM+, CM-, CS+, CS-
V
CM+
- V
CM-
and
V
CS+
- V
CS-
V
CS+
- V
CS-
3.45
160
1.0
1.0
1.0
1.0
0.4
0.4
1.3
4.0
1.3
35
26
3.85
V
°C
V
BST
- V
LX
forced to 5V
High state (pullup)
3.5
4.5
3.5
4.5
1.0
2.0
Ω
DL Gate-Driver On-Resistance
(Note 4)
R
ON(DL)
Low state (pulldown)
Ω
DH Gate-Driver Source/Sink
Current
DL Gate-Driver Sink Current
DL Gate-Driver Source Current
Dead Time
I
DH
I
DL
I
DL
DH forced to 2.5V, V
BST
- V
LX
forced to 5V
DL forced to 2.5V
DL forced to 2.5V
DL rising
DH rising
A
A
A
ns
_______________________________________________________________________________________
3
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
