Pmics with dynamic core for pdas and smart phones, Electrical characteristics (continued) – Rainbow Electronics MAX1587A User Manual
Page 9
MAX1586A/MAX1586B/MAX1587A
High-Efficiency, Low-I
Q
PMICs with
Dynamic Core for PDAs and Smart Phones
_______________________________________________________________________________________
9
Note 1: Dropout voltage is guaranteed by the P-channel switch resistance and assumes a maximum inductor resistance of 45mΩ.
Note 2: The PWM-skip-mode transition has approximately 10mA of hysteresis.
Note 3: The maximum output current is guaranteed by the following equation:
where:
and R
N
= N-channel synchronous rectifier R
DS(ON)
R
P
= P-channel power switch R
DS(ON)
R
L
= external inductor ESR
I
OUT(MAX)
= maximum required load current
f = operating frequency minimum
L = external inductor value
I
LIM
can be substituted for I
OUT(MAX)
(desired) when solving for D. This assumes that the inductor ripple current is
small relative to the absolute value.
Note 4: POK only indicates the status of supplies that are enabled (except V7). When a supply is turned off, POK does not trigger
low. When a supply is turned on, POK immediately goes low until that supply reaches regulation. POK is forced low when all
supplies (except V7) are disabled.
Note 5: Specifications to -40°C are guaranteed by design, not production tested.
D
V
I
R
R
V
I
R
R
OUT
OUT MAX
N
L
IN
OUT MAX
N
P
=
+
+
+
−
(
)
(
)
(
)
(
)
I
I
V
D
x f x L
R
R
D
x f x L
OUT
LIM
OUT
N
L
max
(
)
(
)
(
)
=
−
−
+
+
−
1
2
1
1
2
ELECTRICAL CHARACTERISTICS (continued)