Datasheet
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ELECTRICAL CHARACTERISTICS
DC/DC CONTROLLER SECTION
TPS23750
TPS23770
SLVS590B – JULY 2005 – REVISED FEBRUARY 2008
Characteristics are for: – 40 ° C ≤ T
J
≤ 125 ° C; V
DD
– V
SS
= 48 V. V
DD
, CLASS, and DET referenced to V
SS
, and all
other pin voltages are referenced to RSN, COM, and RTN shorted together unless otherwise noted.
SEN=MODE=BL=RSP=RTN, FB=V
BIAS
, SENP=V
DD
, C
TMR
= 1000 pF, C
VBIAS
= 0.1 µ F, C
VAUX
= 0.1 µ F,
R
FREQ
= 150 k Ω , R
DET
= 24.9 k Ω , R
CLASS
= 255 Ω , GATE is unloaded, and V
BIAS
and AUX have no external loads
unless otherwise noted.
RTN = V
SS
for this section only.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
BIAS SUPPLY (VBIAS)
V
BIAS
Output voltage 0 ≤ I
LOAD
≤ 5 mA 4.60 5.1 5.5 V
AUX SUPPLY (AUX)
V
AUX
Supply output voltage 18 V ≤ V
VDD – COM
≤ 57 V, 0 mA ≤ I
AUX
≤ 10 mA 9 10 11 V
Current limit V
AUX
= 0 V 12 23.5 28 mA
OSCILLATOR (FREQ)
R
FREQ
= 30 k Ω , V
COMP
= 3.9 V, MODE = V
BIAS
, Measure GATE 48.8 49.2 49.5 %
D
MAX
Maximum duty cycle
voltage at 50% rising to 50% falling
MODE = V
BIAS
, V
COMP
= 3 V, Measure at GATE
f
OSC
Oscillator frequency R
FREQ
= 30 k Ω 435 487 565 kHz
R
FREQ
= 150 k Ω 90 100 110
ERROR AMPLIFIER (FB, COMP)
COMP source current 0 ≤ V
COMP
≤ 4 V, FB = RTN, V
TMR
= 2.5 V 2.5 mA
COMP sink current 1.2 V ≤ V
COMP
≤ V
BIAS
, V
TMR
= 2.5 V 2.4 mA
V
REF
FB regulation voltage V
COMP
= 2.5 V, V
TMR
= 2.5 V 1.47 1.50 1.53 V
Open loop voltage gain 1.2 V ≤ V
COMP
≤ 4 V, V
TMR
= 2.5 V 80 dB
Small signal unity gain bandwidth V
COMP
= 2.5 V, V
TMR
= 2.5 V 1.5 2 MHz
COMP input resistance MODE = V
BIAS
, 1.1 ≤ V
COMP
≤ 4.4, V
TMR
= 2.5 V 70 100 130 k Ω
FB leakage (source or sink) 0 ≤ V
FB
≤ V
BIAS
, V
TMR
= 2.5 V 1 µ A
SOFT START TIMER (TMR)
Source current TMR charging, V
TMR
between lower threshold and clamp 38 50 62 µ A
Ratio of source/sink current 9 10 11 -
ON duty cycle MODE = V
BIAS
, V
COMP
= 4.4 V, Second cycle and beyond 8 9.1 10 %
CURRENT SENSE (RSP, RSN, BL)
MODE = V
BIAS
, V
COMP
= 4.2 V, V
TMR
= 2.5 V, Increase 0.46 0.5 0.54 V
Current limit threshold
V
RSP-RSN
until the duty cycle switches from 50% to the minimum
MODE = V
BIAS
, V
COMP
= 4.2 V, V
TMR
= 2.5 V, Increase 0.70 0.765 0.83 V
Fault current threshold
V
RSP-RSN
until no gate pulses occur
V
RSP – RSN
= 0.6 V, V
AUX
= 12 V, MODE = V
BIAS
, V
COMP
= 4.2 V,
V
TMR
= 2.5 V. Measure 50% of V
GATE
↑ to 50% V
GATE
↓
Minimum propagation delay, BL floating 40 60 90
t
BLNK
Current limit delay ns
Blanking period (pulse width above minimum), BL connected to 45 70 95
RSN
Blanking period (pulse width above minimum), BL connected to 70 105 140
V
BIAS
FREQ = V
BIAS
, MODE = V
BIAS
, V
COMP
= 4 V,
RSP current 2.5 4 8 µ A
V
RSP-RSN
= 0.4 V, I
RSP
sourcing
GATE DRIVER (GATE)
5 mA source, V
AUX
= 12 V 11.9
Output voltage swing V
5 mA sink, V
AUX
= 12 V 0.05
Peak source current V
AUX
= 12 V, pulse test 0.33 0.58 0.8 A
Peak sink current V
AUX
= 12 V, AC test or pulse test with TMR = RSN 0.7 1.0 1.3 A
VOLTAGE TRANSLATOR (SEN, SENP)
V
TMR
= 2.5 V, Measure with servo loop that includes the error
(SENP - SEN) regulation voltage 1.456 1.492 1.526 V
amplifier
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