XR79103EL-F Datasheet, PDF (13/20 Pages) Exar Corporation – 22V, 3A Synchronous Step-Down COT Power Module

V1IN.0×6 _{x[tOf ×NVE}–_OffU(.2T.5 × 10 )]
RROONNtO==N
=
VIN
V×IN[2t×O.7N18.0_–(x26.1(72x08.^-_5f¹Ã—⁰_×1E10f0f^-.^1-80_))]
RON =
2.78 x 10^-10
(IOCP +VO(0U.T5 × ∆IL))
RtLOINM==
VIN1×.061VV.x0OORI6LUfUDI×TMxTSfE×ff.
Ef_–f.
+
[(2.5
0.16kΩ
× 10^-8)
×
VIN]
Applications^tOI^RNn^Of^=No⁼rVm_INa×t1io.0n6 x(Cf(×2o.7En8fft.×in1u0^-e¹⁰)d)
Programming the Output Voltage
Uprsoegraanmetxhteeronua_RtlpORuNv_Lot_=Ilv_Mtao₌g_{11lt..ae00g66(}d^VV_eIOxxiOOv_CVUUffi_Pd_O××TTe_+UEEr_{(TRI2ff(Lff.0}a_D...I7M.s_{S58––}s_××[[h_((22∆1o_..0I55w_L-1)××n₎₀₎
1ⁱⁿ0^-8F) ⁱ×^guV^r_IN^e]
+ 0.16kΩ
10^-8) × VIN]
27
to
RORNFB=1 _{= RFB2 × (V20O..76U8VT×–101-10)}
(IOCP + (0.5 × ∆IL))
Where R_FB2 ha^RsLIMa n⁼ominal vaILlu_IMe of 2kΩ. ^{+ 0.16kΩ}
π ^{pofPPorfrlloalo}otgc^Sgwer^Sraia,nammgccat^meahlqcpe^iunuasla^gcaoRtitti^tfeoLothC-ICnr^{MseSFt:RCthSFa=SFeSr==BotS.1frt(2SteIIb=On-Sq}×^{SeCRuot×tPwFairrBd+ree}×2^te1edRRI0(LrR00×DD^{n.I6M.FµtcSS51oVBAtah×1Vpp0eOxar.∆6oUSc}5IV^gLTiStx)^ra)af^n–a_L^mc+_C^{n1eda0.AC1s6oGSkfSNtΩ-sDftraoprmtintsitmhteeo}
CSS
RFfLBC1==
= tSS
RFB2
2x
×
×
πx
10µA
√^{V001OL..66UxVVTCO–}_UT1
ππ ^{ππ FpCThehaaeelcsdfuee-lFaeotdmer-fwaCorarFgwrFindafrrCRCCdoCwRFSSFmacFBSShFpCaFf1eLt===aFph=Cn=Fcaett2SS=i=cR2tSSfui}×^{oFotxso2B××rllir22on×(CC}×^{wg×xx11100FFifR00n..FF×66cxFµµg)xV1iVVe}_B0AAC^sRO√.e₁^{rFF6Uau1q1FBVLxTmsu15xeaixcd–Cxti5Oot}f1^o_LU^{onxCTu:sfLtepCtutht ecnaepcaecsitsoarrsy.}
π Where
f_LC,
the^CFFou⁼tp2u×t
1
fil×teRr_FBd₁oxu5blxe-fLp_Cole
frequency
is
calculated
from:
fLCR=FF
=
2
2x
x_ππx
11
x_√fLxxCCFOFUT
fLC =
1
2 x π x √ L x COUT
π ^{YdeotuermminuestthueseefR}_fe^FmcF_ta⁼_ivneu2^fcax_acptuax1^rcf^eitx^ra’C^sn_{FcFeDCcorrdeesrpaotinndgincgutrovVesOU}^t_T^o.
π ^{A load}
should
bseteppertfeosr^Rmt^FFeadn^=da/2no^xdr
a ¹loop frequency response test
if^xn^fe^xce^CsFFsary C_FF can be adjusted
in order to get a critically damped transient load response.
In certain conditions an alternate compensation scheme
may need to be employed using ripple injection from
the inductor. Those components; RR, CR, and CAC
are shown in Figure 27. An application note is
being developed to provide more information about this
compensation scheme.
0.6V
CSS = tSS ×
10µA
0.6V
XR79103
CFF
=
2
×
π
×
1
RFB1
x
5
x
fLC
π ^F_fRr^e_e^Fe_q^F,d_ue^-iFnno_cc^r_yo^wnpajourd_lnec^Rtaieof_n^LsndCisw=t_a^oidthr_d2⁽_s^RCx^FF_g^FF_a^),x_inf√^u1_mL^ncx_atC^irog_Oⁿⁱ_UnsT
similar
to the
to a high
frequency
response. Calculate R_FF from:
RFF
=
2x
π
1
xf
x
CFF
Where f is the switching frequency.
If R_FF > 0.02 x R_FB1 then calculate R_FF value from
R_FF = 0.02 x R_FB1.
Maximum Allowable Voltage Ripple at FB Pin
Note that the steady-state voltage ripple at feedback pin FB
(V_FB,RIPPLE) must not exceed 50mV in order for the module
to function correctly. If V_FB,RIPPLE is larger than 50mV then
C_OUT should be increased as necessary in order to keep
the V_FB,RIPPLE below 50mV.
REV1B
13/19