Datasheet

MAX5068
High-Frequency, Current-Mode PWM Controller
with Accurate Programmable Oscillator
_______________________________________________________________________________________ 3
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
CS Input Bias Current I
B_CS
V
CS
= 0V 0 +2 µA
CS Blanking Time t
CS_BLANK
70 ns
Propagation Delay from
Comparator Input to NDRV
50mV overdrive 40 ns
IN CLAMP VOLTAGE
IN Clamp Voltage V
IN_CLAMP
V
IN
sinking 2mA (Note 2) 24.0 26.0 29.0 V
ERROR AMPLIFIER (FB, COMP)
Voltage Gain A
V
R
COMP
= 100kΩ to AGND 80 dB
Unity-Gain Bandwidth BW
R
COMP
= 100kΩ to AGND,
C
LOAD
= 100pF to AGND
5 MHz
Phase Margin PM
R
COMP
= 100kΩ to AGND,
C
LOAD
= 100pF to AGND
65 degrees
FB Input Offset Voltage V
OS_FB
3mV
High 2.6 3.8
COMP Clamp Voltage V
COMP
Low 0.4 1.1
V
Error-Amplifier Output Current I
COMP
Sinking or sourcing 0.5 mA
+25°C ≤ T
A
≤ +125°C (Note 3) 1.215 1.230 1.245
Reference Voltage V
REF
-40°C ≤ T
A
≤ +125°C 1.205 1.230 1.242
V
Input Bias Current I
B_EA
100 300 nA
COMP Short-Circuit Current I
COMP_SC
12 mA
THERMAL SHUTDOWN
Thermal-Shutdown Temperature T
SD
+170 °C
Thermal Hysteresis T
HYST
+25 °C
OSCILLATOR SYNC INPUT (MAX5068A/B/C/E Only)
SYNC High-Level Voltage V
IH_SYNC
2.4 V
SYNC Low-Level Voltage V
IL_SYNC
0.4 V
SYNC Input Bias Current I
B_SYNC
10 nA
Maximum SYNC Frequency f
SYNC
f
OSC
= 2.5MHz (Note 4) 3.125 MHz
SYNC High-Level Pulse Width t
SYNC_HI
30 ns
SYNC Low-Level Pulse Width t
SYNC_LO
30 ns
DIGITAL SOFT-START
Soft-Start Duration t
SS
(Note 5) 2047 cycles
Reference-Voltage Step V
STEP
9.7 mV
Reference-Voltage Steps During
Soft-Start
127 steps
OSCILLATOR
Internal Oscillator Frequency
Range
f
OSC
f
OSC
= (10
11
/ R
RT
) 50 2500 kHz
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= +12V for the MAX5068B/E/F; V
IN
= +23.6V for the MAX5068A/C/D at startup, then reduces to +12V; C
IN
= C
REG5
= 0.1µF;
C
VCC
= 1µF; R
RT
= 100kΩ; NDRV = floating; T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)