MAX8660BETL+ Maxim Integrated Products, MAX8660BETL+ Datasheet - Page 32

• Manufacturer Part Number: MAX8660BETL+
• Description: Other Power Management Low-IQ PMIC w/Dynamic V Mgt
• Manufacturer: Maxim Integrated Products

Specifications of MAX8660BETL+

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

High-Efficiency, Low-I
Voltage Management for Mobile Applications
When the V
MAX8660/MAX8661 enter its undervoltage-lockout
mode (UVLO). UVLO forces the device to a dormant
state. In UVLO, the input current is very low (1.5µA)
and all regulators are off. RSO and LBO are forced low
when the input voltage is between 1V (typ) and V
The I
contents are reset in UVLO.
When the input voltage is above V
the MAX8660/MAX8661 enter overvoltage-lockout mode
(OVLO). OVLO mode protects the MAX8660/
MAX8661 from high-voltage stress. In OVLO, the input
current is 25µA and all regulators are off. RSO is held
low, the I
reset in OVLO. LBO continues to function in OVLO; how-
ever, since LBO is typically pulled up to V8
( VCC_BBATT ), LBO appears to go low in OVLO because
V8 is disabled. Alternatively, LBO may be pulled up to IN.
RSO is an open-drain reset output. As shown in Figure
1, RSO typically connects to the nRESET input of the
applications processor and is pulled up to V8
( VCC_BBATT ). A low on nRESET causes the processor
to enter its reset state.
RSO is forced low when one or more of the following
conditions occur:
• MR is low.
• V8 is below V
• V
• V
RSO is high impedance when all of the following condi-
tions are satisfied:
• MR is high.
• V8 is above V
• V
• The RSO deassert delay (t
When RSO goes low, the MAX8660/MAX8661 I
ters are reset to their default values.
If the MR feature is not required, connect MR high. If
the RSO feature is not required, connect RSO low.
LBO is an open-drain output that typically connects to the
nBATT_FAULT input of the applications processor to indi-
cate that the battery has been removed or discharged
(Figure 1). LBO is typically pulled up to V8 ( VCC_BBATT ).
32
expired.
IN
IN
UVLO
______________________________________________________________________________________
2
C does not function in UVLO, and the I
is below V
is above V
and Undervoltage-Lockout Functions
2
C does not function, and register contents are
< V
IN
IN
Undervoltage and Overvoltage Lockout
Low-Battery Detector (LBO, LBF, LBR)
is below V
< V
RSOTH
RSOTH
UVLO
OVLO
OVLO
Reset Output (RSO) and MR Input
(2.35V typ).
(6.35V typ).
(2.2V falling typ).
Voltage Monitors, Reset,
(2.35V rising typ).
.
UVLO
VBHRSTH
(typically 2.35V), the
OVLO
= 24ms typ) has
(typically 6.35V)
2
C register
2
C regis-
Q
UVLO
, PMICs with Dynamic
.
LBR and LBF monitor the input voltage (usually a bat-
tery) and trigger the LBO output (Figure 7). The truth
table in Figure 7 shows that LBO is high impedance
when the voltage from LBR to AGND (V
the low-battery rising threshold (V
LBO is low when the voltage from LBF to AGND (V
falls below the low-battery falling threshold (V
1.20V typ). On power-up, the LBR threshold must be
exceeded before LBO deasserts.
Connecting LBF to LBR and to a two-resistor voltage-
divider sets a 50mV hysteresis referred to LBF (hystere-
sis at the battery voltage is scaled up by the resistor
value), connecting LBF and LBR separately to a three-
resistor voltage-divider (Figure 7) allows the falling
threshold and rising threshold to be set separately
(achieving larger hysteresis). The Figure 7 resistor val-
ues are selected as a function of the desired falling
(V
First, select R3 in the 100kΩ to 1MΩ range:
Figure 7. Low-Battery Detector Functional Diagram
+
LBOF
) and rising (V
R2
R3
R1
R
R
1
2
=
=
IN
LBF
LBR
R x
R x
V
V
V
V
LBF
LBF
LBF
LBF
3
3
LBF
< V
< V
> V
> V
V
1.200V
V
1.250V
LBFTH
LBRTH
LBFTH
LBFTH
LBFTH
LBFTH
LBOR
⎛
⎜
⎝
V
V
V
V
LBRTH
LBOR
LBFTH
LBRTH
) thresholds as follows:
MAX8660
MAX8661
TRUTH TABLE
V
V
V
V
LBR
LBR
LBR
LBR
S
R
LBR
< V
> V
< V
> V
x
x V
x V
LBRTH
LBRTH
LBRTH
LBRTH
Q
⎛
⎜
⎝
1
LBOR
LBOF
−
LBRTH
V
V
LBFTH
LBOF
HOLD
−
LBO
0
0
1
LBR
= 1.25V typ).
1
⎞
⎟
⎠
LBO
AGND
⎞
⎟
⎠
) exceeds
LBFTH
(VCC_BBATT)
V8
LBF
=
)