LTC3838-2_15 Datasheet, PDF (3/56 Pages) Linear Technology – Dual, Fast, Accurate Step-Down DC/DC Controller with xternal Reference Voltage and Dual Differential Output Sensing

LTC3838-2
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T_A = 25°C. V_IN = 15V unless otherwise noted (Note 3).
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Main Control Loops
V_IN
V_OUT1,2
I_Q
V_FB1
V_FB2
Input Voltage Operating Range
Regulated Output Voltage Operating Range
Input DC Supply Current
Both Channels Enabled
Only One Channel Enabled
Shutdown Supply Current
Regulated Feedback Voltage on Channel 1
(V_OUTSENSE1+ – V_{OUTSENSE1–})
Regulated Feedback Voltage on Channel 1
Over Line, Load and Common Mode
Regulated Feedback Voltage on Channel 2
(2 • V_DFB2+ – V_DFB2–)
Regulated Feedback Voltage on Channel 2
Over Line, Load and Common Mode
I_VOUTSENSE1+
I_{VOUTSENSE1–}
I_EXTVREF2
V_EXTVREF2
V_OUTSENSE1+ Input Bias Current
V_{OUTSENSE1–} Input Bias Current
EXTV_REF2 Input Bias Current
Maximum EXTV_REF2 Input Operating Voltage
I_VDFB2+
I_VDFB2–
Minimum EXTV_REF2 Input Operating Voltage
V_DFB2+ Input Bias Current
V_DFB2– Input Bias Current
g_m(EA)1,2
Error Amplifier Transconductance
(∆I_TH1,2 /∆V_FB1,2)
t_ON(MIN)1,2
Minimum Top Gate On-Time
t_OFF(MIN)1,2 Minimum Top Gate Off-Time
Current Sensing
V_{SENSE(MAX)1,2}
Maximum Valley Current Sense Threshold
(V_SENSE1,2+ – V_{SENSE1,2–})
V_{SENSE(MIN)1,2}
I_SENSE1,2+
Minimum Valley Current Sense Threshold
(V_SENSE1,2+ – V_{SENSE1,2–})
(Forced Continuous Mode)
SENSE1,2⁺ Pins Input Bias Current
I_{SENSE1,2–}
SENSE1,2^– Pins Input Bias Current (Internal
500k Resistor to SGND)
4.5
RVV^OOe^UUsp^TT1Se^EcR^Nte^Stgo^{E1uV–la,}_D^tV_F^e_BO^d_2U–^{DT2iffReeregnutliaatlelydwDiitfhfeRreenstpiaelclyt}
to
with
0.6
38
V
5.5
V
MODE/PLLIN = 0V, No Load
RUN1 or RUN2 (But Not Both) = 0V
RUN1 = RUN2 = 0V
ITH1 = 1.2V, V_{OUTSENSE1–} = 0V (Note 5)
T_A = 25°C
T_A = 0°C to 85°C
T_A = –40°C to 125°C
V_IN = 4.5V to 38V, ITH1 = 0.5V to 1.9V,
T_A
= –40°C
–0.5V <
to 125°C (Note
V_{OUTSENSE1–} <
5)
0.5V
V_DFB2– = 0V, ITH2 = 1.2V (Note 5)
EXTV_REF2 = 0.6V, T_A = 25°C
ITH2 = 0.5V to 1.9V, –0.2V < V_DFB2– < 0.2V,
T_A = –40°C to 125°C (Note 5)
EXTV_REF2 = 0.6V, V_IN = 4.5V to 38V
EXTV_REF2 = 1.5V, V_IN = 4.5V to 38V
EXTV_REF2 = 2.5V, V_IN = 5.5V to 38V
V_OUTSENSE1+ = 0.6V, V_{OUTSENSE1–} = 0V
V_OUTSENSE1+ = 0.6V, V_{OUTSENSE1–} = 0V
EXTV_REF2 = 0.6V
V_IN ≥ INTV_CC ≥ 5V, TRACK/SS2 > 2.5V
V_IN ≥ INTV_CC ≥ 4V, TRACK/SS2 > 1.5V
V_DFB2+ = 0.3V, V_DFB2– = 0V
V_DFB2+ = 0.3V, V_DFB2– = 0V
ITH = 1.2V (Note 5)
3
mA
2
mA
15
µA
0.5985 0.6 0.6015 V
l 0.596 0.6 0.604
V
l 0.594 0.6 0.606
V
l 0.591 0.6 0.609
V
0.598 0.6 0.602
V
l 0.596 0.6 0.604
V
l 1.494 1.5 1.506
V
l 2.493 2.5 2.507
V
0 ±25 nA
–25 –50 µA
–5 ±50 nA
l 2.5
V
l 1.5
V
l
0.4
V
0 ±25 nA
–6 –12 µA
1.7
mS
V_IN = 38V, V_OUT = 0.6V, R_T = 20k (Note 6)
(Note 6)
30
ns
90
ns
VVEX^OSEUT_N^{VTSSREEE1NF,S22E–=1}=^{+02=.6.50VV.,5V7DVF,BV2+OU=TS0E.2N8S5E1V–,}
= 0V,
V_DFB2–
=
0V,
l
24
30
36
mV
VVEX^OSEUT_N^{VTSSREEE1NF,S22E–=1}=^{+02=.6.50VV.,6V3DVF,BV2+OU=TS0E.3N1S5E1V–,}
= 0V,
V_DFB2–
=
0V,
–15
mV
VV_SSEENNSSEE++
=
=
0.6V
5V
±5 ±50 nA
1
±2
µA
VV_{SSEENNSSEE––}
=
=
0.6V
5V
1.2
µA
10
µA
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38382f
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