MAX1544 Datasheet, PDF (4/42 Pages) Maxim Integrated Products – Dual-Phase, Quick-PWM Controller for AMD Hammer CPU Core Power Supplies

Dual-Phase, Quick-PWM Controller for
AMD Hammer CPU Core Power Supplies
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V+ = 15V, V_CC = V_DD = V_SHDN = V_TON = V_SKIP = V_S0 = V_S1 = V_OVP = 5V, V_FB = V_CMP = V_CMN = V_CSP = V_CSN =
1.3V, OFS = SUS = GNDS = D0–D4 = GND; T_A = 0°C to +85°C, unless otherwise specified. Typical values are at T_A = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX UNITS
Output Undervoltage Fault and
Measured from the time when FB reaches
VROK Transition Blanking Time
t_BLANK the voltage set by the DAC code; clock
24
Clks
(Note 4)
speed set by R_TIME
VROK Startup Delay
Measured from the time when FB first
reaches the voltage set by the DAC code
3
5
7
ms
after startup
VROK Delay
t_VROK
FB forced 2% outside the VROK trip
threshold
10
µs
VROK Output Low Voltage
VROK Leakage Current
I_SINK = 3mA
High state, VROK forced to 5.5V
0.4
V
1
µA
V_CC Undervoltage Lockout
Threshold
V_UVLO(VCC)
Rising edge, hysteresis = 90mV, PWM
disabled below this level
4.0 4.25 4.4
V
Thermal-Shutdown Threshold
CURRENT LIMIT AND BALANCE
T_SHDN
Hysteresis = 10°C
160
°C
Current-Limit Threshold Voltage
(Positive, Default)
V_LIMIT CMP - CMN, CSP - CSN; ILIM = V_CC
28
30
32
mV
Current-Limit Threshold Voltage
(Positive, Adjustable)
Current-Limit Threshold Voltage
(Negative)
V_LIMIT
CMP - CMN, CSP - CSN ^{VILIM = 0.2V}
V_ILIM = 1.5V
V_LIMIT(NEG)
CMP - CMN, CSP - CSN; ILIM = V_CC,
SKIP = V_CC
8
10
12
mV
73
75
77
-41
-36
-31
mV
Current-Limit Threshold Voltage
(Zero Crossing)
V_ZERO CMP - CMN, CSP - CSN; SKIP = GND
1.5
mV
CMP, CMN, CSP, CSN Input
Ranges
0
2
V
CMP, CMN, CSP, CSN Input
Current
V_CSP = V_CSN = 0 to 5V
-2
+2
µA
Secondary Driver-Disable
Threshold
ILIM Input Current
Current-Limit Default Switchover
Threshold
V_CSP
I_ILIM
V_ILIM
V_ILIM = 0 to 5V
3
V_CC - 1
V_CC -
0.4
V
0.1
200
nA
3
V_CC - 1
V_CC -
0.4
V
Current-Balance Offset
(V_CMP - V_CMN) - (V_CSP - V_CSN); I_CCI = 0,
V_OS(IBAL) -20mV < (V_CMP - V_CMN) < 20mV,
-2
1.0V < V_CCI < 2.0V
+2
mV
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