Datasheet

3
LTC1923
1923f
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are T
A
= 25°C.
V
DD
= 5V, R
SLEW
= V
DD
, SDSYNC = V
DD
, R
T
= 10k, C
T
= 330pF unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Reference
V
REF
Reference Output Voltage No Load 2.462 2.5 2.538 V
● 2.450 2.550 V
V
REFGD
V
REF
Good Threshold V
REF
Rising Threshold ● 2.25 2.45 V
LDREG Load Regulation I
LOAD
= –1mA to –10mA 10 25 mV
LINEREG Line Regulation V
DD
= 2.7V to 5.5V 5 20 mV
V
REFISC
Short-Circuit Current V
REF
= 0V 10 20 mA
Oscillator and Phase-Locked Loop
f
OSCI
Initial Oscillator Frequency R
T
= 10k, C
T
= 330pF 190 225 260 kHz
f
OSC
Frequency Variation V
DD
= 2.7V to 5V, C
T
= 330pF, R
T
= 10k ● 165 225 270 kHz
OSCPK C
T
Ramp Peak 1.4 1.5 1.6 V
OSCVLY C
T
Ramp Valley 0.4 0.5 0.6 V
C
TICH
C
T
Charge Current C
T
= 0.3V, R
T
= 10k –150 µA
C
TIDIS
C
T
Discharge Current C
T
= 1.8V, R
T
= 10k 150 µA
PLLGAIN Gain from PLLLPF to R
T
–1.1 –0.9 –0.7 V/V
I
PLLLPF
Phase Detector Output Current
Sinking f
SYNC
< f
OSC
12 µA
Sourcing f
SYNC
> f
OSC
–12 µA
MSTTH Master Threshold On PLLLPF Pin Measured at SDSYNC Pin V
DD
– 0.7 V
DD
– 0.4 V
SDDLY Shutdown Delay to Output 20 45 µs
Error Amplifier
V
OS
Input Offset Voltage EAOUT = 1V, V
CM
= 2.5V –18 18 mV
AOL Open-Loop Gain EAOUT = 0.45V to 1.55V, CNTRL = 2.5V 80 dB
V
CM
Common Mode Input Range EAOUT = 1V 0.2 V
DD
+ 0.2 V
I
IB
FB and CNTRL Input Bias Currents FB = CNTRL = 1.25 –100 100 nA
V
OH
Output High I
LOAD
= –100µA 1.65 V
V
OL
Output Low I
LOAD
= 100µA 0.3 0.45 V
I
SOURCE
Sourcing Current EAOUT = 1V, FB = 2.4V, CNTRL = 2.5V –1.5 –0.5 mA
I
SINK
Sinking Current EAOUT = 1V, FB = 5V, CNTRL = 2.5V 1 2 mA
GBW Gain-Bandwidth Product f = 100kHz (Note 3) 2 MHz
Current Sense Amplifier
ACS Amplifier Gain 10 V/V
CSOFF Amplifier Offset Measured at I
TEC
–15 –2 10 mV
I
TECH
Output Sourcing Load Regulation CS
+
- CS
–
= 100mV, I
LOAD
= 0 to –50µA 0.1 0.2 V
I
TECL
Output Sinking Load Regulation CS
+
- CS
–
= 100mV, I
LOAD
= 0 to 50µA 0.1 0.2 V
f3dB –3dB Frequency (Note 3) 500 kHz
I
LIMTH
Current Limit Threshold Measured at CS
+
, CS
–
● 125 145 165 mV
I
LIMDLY
Current Limit Delay to Output 300 450 ns
SSI
CHG
Soft-Start Charge Current SS = 0.75V –2.5 –1.5 –0.5 µA
SSI
LIM
Soft-Start Current Limit Threshold SS = 0.5V, Measured at CS
+
, CS
–
50 70 90 mV
I
LIM
I
LIM
Current Limit Threshold I
LIM
= 0.5V, Measured at CS
+
, CS
–
50 70 90 mV